Can It Be this SIMPLE?

[Mike_Lynch]

OK I have a Childs Electric Powered GO KART, ( Peg-Perego / Power Wheels type thing ) that I'm doing a
REBUILD / HOP-UP on for my 3 year old nephew. The thing came with a single 6 Volt battery and runs
forward by pressing a button on the steering wheel. I'm adding NOS / Turbo by installing a second
6 Volt battery in series. ( Insane I know but see this site http://www.modifiedpowerwheels.com/ ).
Also Wired in a switch for a powered reverse.
( see MY circuit and explanation at http://home.comcast.net/~david.lynch1/GoKartCkt.html )

Anyway I'm posting here with a question about some code I just hacked out to controle a
6 Volt ONLY "Soft Start" so the little one can't hold down the "NOS / Tutbo" button and step
on the "GAS Pedal" & end up launching form a dead stop to 12 Volts in an instant.
On the matter of 12 Volts burning up the motor, word is that most of these motors are 18 Volts.

My thought is to use a PIC12F675 to check voltage at the motor & if it's 6 or 12 volts
then it's OK for the "Go Faster" button to be pressed, the PIC needs to do nothing
except loop back to check again. BUT, if the motor voltage is 0 (zero) then the thing
is standing at a stop and if the Go Fast button is pressed when the gas pedal is pressed
I want to use a relay to disable the 12 Volts for some period of time, and allow the thing to
start at 6 Volts then release the relay and apply the full 12 Volts

Now ASSUMING that I have all my registers set properly and constants and variables
declaired, is the CODE as SIMPLE as this or have I COMPLEATLY missed it?


start:
ADCIN 0, Motor_Volts

If Motor_Volts > 0 THEN start ' do nothing as SOME voltage exist at the motor
' and we really don't care if the voltage goes from
' 6V+ to 12V+, that is what it is intended to do

ELSE
IF Motor_Volts = 0 THEN Delay_12V
ENDIF

GOTO start ' do we NEED this statement?

END

Delay_12V:

Motor_V2 = Motor_Volts

WHILE Motor_V2 = 0 ' as long as the motor voltage is at zero volts
' we want to engage the RELAY which disables
HIGH 12Volt_Cancel_Relay_OutPin ' 12 Volts from getting to the motor so we do not
' have a HARD start from zero directly to 12 Volts

ADCIN 0, Motor_V2

WEND

PAUSE 3000

LOW 12Volt_Cancel_Relay_OutPin

GOTO start

[sayzer]

First of all others,

It is very difficult to get 0 volt on the motor.

It might be done by short-circuit on the motor terminals but it is not safe for the motor. The motor life will be shorther then the life of a butterfly.

A powerfull resistor on terminals could be useful but again you will not get zero volt.

You may want to adjust that part a little by experimenting.




Word History: Is a butterfly named for the color of its excrement or because it was thought to steal butter? It is hard to imagine that anyone ever noticed the color of butterfly excrement or believed the insect capable of such theft. The first suggestion rests on the fact that an early Dutch name for the butterfly was boterschijte. The second is based on an old belief that the butterfly was really a larcenous witch in disguise.
How about that?

[Luciano]

Hi,

Wear a safety helmet!

With a full-face helmet or an helmet + protective chin cup
you will also provide protection to teeth.

Be careful!

Here the button "Go Faster" under the table was pressed!
http://www.dentistsw4.co.uk/gifs/treatments/chip1.jpg

* * *
What about using the PWM of the PIC?

Versatile DC Motor PWM Speed Controller:
(This example does not use a PIC to generate the PWM).

Part 1:
http://sound.westhost.com/appnotes/an009.htm
Part 2:
http://sound.westhost.com/appnotes/an009-2.htm

By using the PWM of the PIC you can set the right speed for the
child using the toy. (Next year you can set an higher speed).

This is done by changing the PWM duty cycle. By changing PWM duty
cycle you can set the motor to any speed and therefore create any
personalized acceleration curve.

(You will need a PIC with hardware PWM).

Best regards,

Luciano

[Melanie]

If I was a three-year-old, I'd want to experience the joys of burning rubber from a standing start... pass the 24v truck batteries... (then they can grow up and build drag-racers)...

Why bother with a PIC with the associated problems of Power Supply and Motor noise etc etc? Just a time-delay relay that enables operation of the turbo button a few seconds after power has been applied.

[Luciano]

..... experience the joys of burning rubber from a standing start...

I am not sure she would agree with you....
http://img10.picsplace.to/15/maid.PNG (http://picsplace.to/)

Luciano

[sayzer]

... (then they can grow up and build drag-racers)....

Why wait to grow up?

http://img4.picsplace.to/img4/25/thumbs/kidracer.jpg (http://img4.picsplace.to/img.php?file=img4/25/kidracer.jpg)

[Mike_Lynch]

Luciano.
First, do I even want to know what someone was doing “Going Faster under the Table” ?
Secondly, thanks for those links, I wonder If I could getaway with placing TWO
Variable Resistors in the circuit and using a relay triggered by the “Turbo” button to
switch between them? I’ll have to look into that as a possible solution.

“Next year you can set an higher speed.”
Good Idea if I could expect this thing to last a year. See the section of my reply to Melanie regarding PLASTIC.
While I was out earlier today I stoped at a GoodWill Store and found the kids NEXT ride “Barbie” QuadRider,
( Almost Brand NEW, No battery charger, no big deal. ) $10.00 (USD) amazing what people here “throw out”.
YEA “Barbie”(purple, pink & white) a few cans of spray paint will take care of THAT foolishness. 8-)
TWO 12 Volt motors on this thing, one on each rear wheel.
Compared to the GO Kart it’s a MONSTROUSLY large thing.
Neighborhood kids on foot and small animals will need to LOOK OUT ! ! !

Mel,
“If I was a three-year-old, I'd want to experience the joys of burning rubber from a standing start...”
Yea me too, but that’s real BAD on the PLASTIC Gearbox, as a matter of fact except for the motor, batteries,
axels and a few bits for steering linkage, the WHOLE DARN THING is plastic, Even the hollow wheels.
I’m glad I’m NOT the one who paid close to $200.00 USD retail for it. Someone lost the original battery
charger and chucked it into the Salvation Army donation box. I paid $8.00 for the thing.

If he were MY kid instead of my Sister’s he would have been real bored with this thing by three years
old because I would have started him on it at 6 months, 8 months at the outside.
WE DON’T NEED NO STINKING STROLLER ! ! ! 8-)
He would be racing GAS (Petrol) powered Go-Carts by NOW.

“Why bother with a PIC with the associated problems of Power Supply and Motor noise etc etc?”
Why bother with a PIC? I’ve got them in the parts bin collecting dust. I guess the REAL answer to that
one is my personal PicBasic experience / educ-tainment, (education + entrtainment) something I want to
have the experience of “under my belt / in my bag of tricks”.

“Just a time-delay relay that enables operation of the turbo button a few seconds after power has been applied.”
The kid needs to learn the difference in speeds first hand, I believe he already has some concept of the fact that he
can’t drive “Flat Out / Wide Open” all the time from he and his Dad playing with slotcars & NASCAR Videogames.

Although I have NO doubt that this thing will spend 90% or more of it’s running time in 12 volt
“Turbo Mode” If a time delay relay is used then there is no driver control over which speed he is going.
Also if you look at the schematic notes I posted the circuit as it stands right now has a “Parental Override”,
a 12 Volt lockout, probably nothing more than a key switch scavenged from an OLD PC Case, wired in series
with the “Turbo” button in the event his parents feel the 12 Volts is too fast for the kid to have access to from the beginning.

I hope you were thinking something along the lines of a NE555 as a timer for that Time Delay Relay,
I haven’t looked HARD, but when I look at Digikey those things are in the $100.00 and up range

This is a LOW BUDGET project,
( Prices listed in USD)
Vehicle = $08.00 Salavtion Army Store
Batteries = $05.00 (each) 2 x 12 Volt 12 Ah local Electronics Surplus Store
PIC = $02.00 Had on hand in the parts bins
Relays = $??.?? Had on hand from YEARS ago when local parts retailer closed
Car Wash = $01.75 DIY Carwash High Pressure stuff, had to blast off the cobwebs & crud
Battery Charger = $??.?? Had a box of power supplies & high current wall warts on hand.
Wire & Switches = $??.?? Had on hand 10 & 12 AWG wire and switches left over from another project

Look on the kids face when he’s ripping down the driveway and finds the Turbo, = PRICELESS ! ! !

My Brother in Law and I have TALKED about adding RC Controls to one of the full sized
Power Wheels JEEP and sticking the kid in that so we can steer him where we want him to
go instead of where he wants to go. Don’t know if that will ever happen but I’m keeping my
eyes open for a free or cheap JEEP in good condition.

[Melanie]

When I meant a Time-Delay Relay on the turbo switch, I meant that the Relay contacts were is SERIES with the switch and not in parallel with it. i.e., until the Relay threw, the turbo switch was out of circuit. Only AFTER the Relay closed, only then the turbo switch could be pressed if desired.

This way, the Time-Delay Relay is simply connected across the Motor, so when power is applied to the motor, the Relay then times and then after a preset time period closes it's contact enabling the turbo button if so desired. If you take power off the motor, the Relay drops out ready for a new timing cycle.

A couple of transistors, a Capacitor and a splattering of Resistors and you've got your circuit for about $1, no PIC, no software, and pretty much supply voltage independant with no worries about having to generate a clean 5v supply for the PIC.

[Mike_Lynch]

Melanie,

Thanks for explaining what you meant. My first reaction was to ask for a schematic,
but I want to stir some brain cells and actually THINK about what it is you are describing.
(Amazingly Sad how rusty I am on this stuff these days, if you don’t use it you LOSE it.)
I’ll have to sit down with pen & paper to see what I come up with before I come BEGGING
and have to bother you for a schematic. 8-)

Thanks
Mike_L

[Archangel]

When my Daughter was about that age I bought her a Suzuki JR50 motorcycle which she rode exactly once. Too much power and she bailed off never to ride again. So here's a suggestion: install a 1/4 inch headphone jack on the rear of this vehicle, break the power connection and wire it through the jack. the plug that mates gets a string attached to Dad or Grandpa. short the inner to the outer conductor of the plug. when it's plugged in he has power, if it gets away from him, the plug pulls out and it stops. You could get creative and use a shorting type jack so instead of stopping it switches to low power. I doubt
Dale Earnhart JR's. first ride was souped up very much.

RULE 1, SAFETY FIRST (Especially with kids)
RULE 2. Go back to rule 1

[Acetronics2]

Hi, Joe

I see something ... a DC motor Torque is a major function of the drawn current ...

soooo, limiting the Max current is a fair way to achieve your goal.

Now how ??? ... Mosfets have an internal ON resistance ... so, using PWM, just measure the D to S voltage, during the ON state ( 100% will also work ...), exactly as with a shunt ...
A simple comparator will short the gate voltage to ground if overcurrent... and allow to easily trim the limit.

That's what used on Power speed regulators for Electric models ...

now, you DO NOT have PWM aboard ... so, just sample D/S Voltage , say @ 500 hz to 3 KHz ( match to the motor ). Limitation will then be smooth enough.

Using a PIC to slowly automatically increase the PWM rate will add the soft start function ... and you've what you want

AND the MOTOR is SAFELY DRIVEN ...

Alain

[f_lez]

If I was a three-year-old, I'd want to experience the joys of burning rubber from a standing start... pass the 24v truck batteries... .


My daughters 3 and a 1/2, her charger recently died, so I just swapped out the 6v batter for a 12v 17amphr one from a portable car starter, she's soon learned best way to set off is to stand up on it and lean forward........

she be in moto cross in a few years time I'm sure!

[Mike_Lynch]

Well, I dropped a 12V 12Ah Gel Cell into that “Barbie” QuadRider thing.
While testing for broken wires, switches or stripped gearboxes I precariously
balanced about 170 lbs. (ME) on the seat and pressed the switch.
The thing MOVED, only a couple of feet, didn’t want to over tax things.

(So if you are in need of motor / gearbox with a TON of torque, you now know where to look.)

If Gas (Petrol) prices keep going up (* See note below), I may park the van
and drive this thing to work. I’ll just have to leave a WHOLE LOT EARLIER ! 8-)

Gas Prices: Yea I know people in other parts of the world have it a lot worse than
we do in the states, my Gas costs 2.75 ~ 3.00 a Gallon I just have to complain a little
because I remember when I started driving (back when you had to wait for a Dinosaur
to die and decay before you could Fill Up) Gas was 0.57 a Gallon.

[Melanie]

Stop moaning! I fueled this morning and the UK price works out at about US$7.90 a gallon (based on 94p/litre for unleaded and US$1.85 to the pound Sterling). It's dropped a little, beginning of last week it was closer to $8.40.

Actually, since we've got an international audience, let's have a little survey, can we get a few folks posting what today's price for unleaded and diesel is in your country?

[Mike_Lynch]

US$7.90 to $8.40a gallon, OUCH !

But doesn’t YOUR daily driver require HIGH OCTANE AVIATION Fuel ?


Mel's erand runner, Daily Driver

[sayzer]

Stop moaning! I fueled this morning and the UK price works out at about US$7.90 a gallon (based on 94p/litre for unleaded and US$1.85 to the pound Sterling). It's dropped a little, beginning of last week it was closer to $8.40.

Actually, since we've got an international audience, let's have a little survey, can we get a few folks posting what today's price for unleaded and diesel is in your country?


Here:
91 Octane Unleaded : US$2.60/liter (101 Octane US$2.70/liter)
Diesel : US$1.38/liter


What about BigMac prices?

[Acetronics2]

In France , these days, 88 unleaded is ~ 1.65 US$ and 98 UL 1.7 US$

Diesel ??? who's that's for ???

I thought Big Macs were obtained from raw oil ... as Coca-Cola !!!

Sure, their prices raise ...

Alain

[f_lez]

I've seen these gas price threads before, and while interesting, its useless to compare them like for like on 1 item, so what about a TOTAL in $ for the following....

I suggest the following items for this comparison and submit my accurate guestimated figures...


$08.50 1 gallon of gas (100P PER GAL)

$11.00 1 bigmac meal

$02.30 3 ltrs of economy store ice cream (walmart asda, 39p per ltr)

$06.94 1 'nice' 14 inch deep pan (supermarket) (walmart asda 3.68)

$88.00 200gb HD (7200 8mb samsung or equiv) (svp 47ukp)

$10.00 A cheap pair of jeans.... (walmart asda, 5)

Total for this is $126.74

Now what can I expect for a an average joe job like a bus driver?

about 200 in your pocket a week or $370

I dont expect others to be able to guess their housing costs etc, but I spend about $25 a week on fuel costs (ie heating+electricity) and an average rent is about $130 for a small house in the outer green bits, or for a small room in a large city.

[sayzer]

f_lez,

... and you expect us to guess where you live?

[sayzer]

Also, if something stupid happens in Middle East, we will see more of these in streets and highways.

http://img9.picsplace.to/img9/20/thumbs/solar.jpg (http://img9.picsplace.to/img.php?file=img9/20/solar.jpg)

[Luciano]

Hi,

From "my" Bank:

Prices and Earnings
http://www.ubs.com/1/ShowMedia/ubs_ch/wealth_mgmt_ch/research?contentId=103982&name=eng.pdf

Best regards,

Luciano

[f_lez]

f_lez,

... and you expect us to guess where you live?

Sorry!

UK

[f_lez]

Hi,

From "my" Bank:

Prices and Earnings
http://www.ubs.com/1/ShowMedia/ubs_ch/wealth_mgmt_ch/research?contentId=103982&name=eng.pdf

Best regards,

Luciano



Now thats a definitive answer, but I dont know if its right........

It puts a big circle over all of europe as though its all the same and country to country its a real see saw.

My house (mine! I rent) is worth about 120,000 but I can buy the same in bulgaria for about 16,000.

Our wages are higher than poland, hence I live in a city where a year ago I would not have see anyone from poland, now I drive around and pass about 10 polish cars a day full of our countries new labor force (if you want to work for less than the minimum wage...) (Oh and all our taxi's are now becoming turkish driven, but thats because they will pay more to rent the car because they can give up more of their income)

(edit)

I'd just like to add I'm not knocking others, its just an economic statement, of a situation created by our loving leaders foreign policy on european freedoms....(but I cant go work in poland, as I could not afford it.(But I know where to go for an holiday if I want to be treat well for a week at the cost of a dayout over here!)

[Chard]

Stop moaning! I fueled this morning and the UK price works out at about US$7.90 a gallon (based on 94p/litre for unleaded and US$1.85 to the pound Sterling). It's dropped a little, beginning of last week it was closer to $8.40.

Actually, since we've got an international audience, let's have a little survey, can we get a few folks posting what today's price for unleaded and diesel is in your country?

Kingston, Ontario

Regular Gas US$ .85.6 - .90.2 per litre
Diesel US$ .83.8 - .88.3 per litre

[sayzer]

... Our wages are higher than poland, hence I live in a city where a year ago I would not have see anyone from poland, now I drive around and pass about 10 polish cars a day full of our countries new labor force (if you want to work for less than the minimum wage...) (Oh and all our taxi's are now becoming turkish driven, but thats because they will pay more to rent the car because they can give up more of their income)...



In 1970s, Germany needed cheap labor force due to Dutch people who did not want to do dirty jobs. Thus, doors were wide opened to Turkish workers mostly from east part and mostly from villages in which mostly the people had no education at all.

Those Turkish workers did do dirty jobs for Dutch people for years, and Dutch people treated them with almost no respect as if Turkish workers were not even human.

However, as the years passed by, many Turkish workers became business owners in Germany, established successful companies in years, even had brand recognitions, and hired Dutch people to do professional jobs for them as well as dirty jobs.

Now, in connection with the comment above, I would like to state an old Turkish saying.
“One experience is more valuable then one thousand advices”.

So, pls take this old saying into consideration.
Those Polish people you see around may become your boss in a few years. Keep good relations with them.



---------------

[f_lez]

So, pls take this old saying into consideration.
Those Polish people you see around may become your boss in a few years. Keep good relations with them.

---------------

My sons last boss _was_ polish! (a cardboard factory)

Well I dont know if thats a real old saying but its makes sense etc, butI do know that amongst the taxi drivers in our city a few eyebrows are being raised because its upsetting the economy of it ('the job')

Our area has a restriction on the number of taxi's, currently 158(app), if you want one, you have to ask someone who has one to sell you the licence, even though they are not transferable, a workaround for that is you give him the money, he makes you his partner, then he retires, ergo your the only partner the licence is yours.

If you cant afford to do that, you can 'rent', IE work for the licence owner and pay him out of your takings, current rent about 160ukp p week on earnings of about 500. subtract other expenses you take home about 200-250 ukp per week - so an average wage

The influx of labor has ment that they want in on this job,and are willingly paying rent of 250ukp per week!

Maybe they think that was the going rate, but as you can see its caused licence owners to /all/ want 250ukp p week or hit the road!

Some older drivers just wont pay the newer inflated rate, so are being forced out of a job, most who have done it for the last 20 years, and wont get work anywhere else!

Another sour point is to be a driver you have to have a police check to say you are not a mass murderer / child molester etc.

If I was checked tomorrow the check would go back at least 10 years, if I was in this country a year, the check would only go back a year..........

Makes no difference on nationality, you can kill 5 children in your country, get out of jail, and come to england and work on the school bus.........

Now can you see its not a race thing that some of us are annoyed at, its the procedures that our leaders put us through but not others.....

I wont go on about this anymore its got really off topic!

[Luciano]

Hi f_lez,

What's that?

http://paiz.gov.pl/index/?id=de7f47e09c8e05e6021ababdf6bc58e7


Best regards,

Luciano

[Mike_Lynch]

Well this thread certainly took a STRANGE turn. It started off with my asking if a piece
of PBP code I posted was correct / viable, I got a couple of replies that hinted the
code might be workable with slight modifications. Some people suggested the use
of other methods to obtain the required results I was looking for, easier, cheaper,
less complex, all well and good, THANKS.

Then I made the mistake (?) of shooting off my mouth about the price of GAS (Petrol)
and THAT initiated a survey on “transportation fuel cost” (Gas / Petrol per Gal. / Liter)
which in turn appears to have sparked a Geo-Political / Economic discussion among some.

Going back to the TRANSPORTATION issue, SOME peoples perceptions / beliefs in the USA,
are that the slow progression of alternate fuel vehicles is in most part due to the Oil Companies
grip on the political infrastructure here. Those companies have a stake in keeping people
dependent on Crude Oil due to their not having developed much in the way of alternative
energy sources. I just heard the other day that Brazil had obtained their goal
of becoming transportation energy self sufficient.
(http://www.nytimes.com/2006/04/10/world/americas/10brazil.html?ex=1302321600&en=03adc82c67600388&ei=5088&partner=rssnyt )

What is the “alternate energy & transportation” status where you are?
Alternate Fuel, Solar / Solar Electric, Gas (Petrol) / Electric, Hydrogen Fuel Cell, etc, . . .
Don’t forget to tell where you are.

[sayzer]

...which in turn appears to have sparked a Geo-Political / Economic discussion among some.

Going back to the TRANSPORTATION issue, SOME peoples perceptions / beliefs in the USA,are that the slow progression of alternate fuel vehicles is....




Welcome to among "some" Mike_Lynch!

[Luciano]

Hi,

Sugar Cane in Brazil = Uncontrolled Deforestation

* * *

In Italy we just use small cars.

Example:
http://www.fiatpunto.com

Best regards,

Luciano

[Acetronics2]

Hi,

In Italy we just use small cars.

Example:
http://www.fiatpunto.com

Best regards,

Luciano

Hi, Luciano

For once, I do not agree with you ...

The real problem is ...

- must a "Fiat Punto " reach 150 km/h and beat the 1/4 mile record ???

- must we use use an electric tool instead of a manual one ???

- must we Posess the last 4Ghz PC to write mails ???

- must we use a PIC when a couple of transistors are far enough ???

.... and so on ...


Back to this Topic ...

- is it REALLY necessary to have a faster toy than our neighbour ???

Humour ....

Alain

[Mike_Lynch]

Must we have Green & Purple Hair?

Must we have tongue, lip, eyebrow & assorted other body parts pierced?

Must we have a Million dollar house in a 250 Thousand dollar neighborhood?

Must we have 2 BMWs and a Hummer in a Ford, Chrysler / Dodge, GM / Chevrolet,
Volkswagen, Nissan, Toyota Neighborhood?

A Riding lawnmower on a ¼ acre lot?

(Yea, I could go on quite a way too . . . )

“is it REALLY necessary to have a faster toy than our neighbor ???”

Obviously, the answer to all the above is NO.

However I believe it all comes from our desire to stand out from the crowd,
and announce our individuality. Just remember if you do the same thing as
so many others, then you don’t really stand out, you become another member
of that group.

BTW my fastest PC is a 900 Mhz P3, I still use a P2 as a router / gateway and
my cell phone is still
#%^'' %$@# (sorry for the static, I'm breaking up)
ANALOG . . . They Work.

THESE are just observations, no harm / no fowl intended or taken.

[Acetronics2]

may we call ourselves ... responsible ???

heuuuuu ....

Alain

[Melanie]

The answer to all of that Alain is No... but...

There's only one of me, yet I own two cars, one is a small car, the other a large gas-guzzling 4x4 Diesel. If I could get one for a sensible price (instead of the riddiculous prices dealers charge), I'd probably buy a Hummer just because I'd be the only kid on the block with one (the other problem with the Hummer is that Americans have forgotten how to make cars and their build quality is attrocious - GM take notice if you read this forum!).

Which car I chose to drive depends on my mood and where I'm going. If around town I might take the small car, or I just might take the 4x4 because manufacturers spend millions on designing fenders which I consider an under-utilised accessory, and I've found they're great for creating gaps in parking where none previously existed provided there's enough horsepower behind them.

Why should I, as an individual, be asked to economise on energy and minimise pollution when more than half the world doesn't care?

I do my bit... I turn the lights off in the Bedroom when I go to bed (saving 200W), but I keep the air-con running (burning 3kW) because I want to be comfortable. I junked the 28" (300W) widescreen, for a 32" (100W) LCD - saving 200W, a good move but offset by the fact that manufacturing the LCD produced three times as much greenhouse gasses than the glass tubed one.

Do you consciously buy product A because it's 'greener' than product B although it's inferior? Let's get real. I don't want to drive a 'Smart' or today's FIAT 500 or Citroen 2CV equivallent.

When at the end of my days my Grandchildren ask (no, I'm not married and have no children as yet - this is hypotheical) "Grandma what did you do when you were younger?", I want to tell them that "I drove up down motorways at 140mph, burnt fuel at 11/gallon in sound-proofed air-conditioned comfort whilst listening to my favourite music at 110dB". I want to tell them that I was a CONSUMER, I worked hard and in turn made my life comfortable.

[Acetronics2]

Hi, Mel

" I want to tell them .... I worked hard and in turn made my life comfortable. "

That's not - exactly - what I understood from two or three years reading carefully your posts on this forum ...

" bearable " sounds better to me.

Might I take off a couple of your " memories " as examples ??? ...

Now, we should redirect this interesting discussion to " off topic " section , ... may be ...

Alain

[Mike_Lynch]

Out of context quote


. . .When at the end of my days my Grandchildren ask "Grandma what did you do when you were younger?", I want to tell them that "I drove up down motorways . . . . whilst listening to my favourite music at 110dB". . . . .

Are you sure you won’t be telling them
“Eeehhh, What did you say? Speak Up I can’t hear you when you mumble ”

M.L. (Ducking for cover)

[Melanie]

OK guys... I'm replicating this thread in Off-Topic...

We can continue posting on-topic about the technicalities of Mikes Barbie Dragster here...

Did you ever pencil together a circuit with a Time-Delay Relay Mike?

[Mike_Lynch]

Did you ever pencil together a circuit with a Time-Delay Relay Mike?

No, not yet Mel, other higher priorities took over, had to get some dental work done,
then the Water Heater in the house decided to start acting up so I had to attend to that.
I haven’t forgot about it though,

[peterdeco1]

Hi Everybody. Attached is a schematic of a 555 controlled PWM that drives a child's 12V ride on car. This isn't exactly the answer to this thread but maybe can give some ideas. The circuit limits the speed of a 100 RPM motor on the axle to about 25 RPM to keep the car slow. The 1uF cap on pin 5 gives a slight ramp-up delay for smooth starting. Making this cap smaller will eliminate the delay. It's important to use the FR602 fast recovery rectifier across the motor. A standard 6A rectifier will get hot but can be used on the B+ feed from the battery. I used a logic level FET to drive the motor but I'm sure a standard FET would work the same. The heatsink on the FET doesn't have to be big either - it's rated at about 40 amps with a very low on resistance. Hope this helps.

[Mike_Lynch]

Something like this perhaps? Shaded areas show what is new to the circuit.

[Melanie]

Yes that's good...

Very clever that you've ensured you can't go TURBO in Reverse - I had to think for a moment what you'd done there!

One observation, R3 isn't needed where you've drawn it, but it IS needed in series with R1, to ensure you don't ever apply full 12v non-current limited to the base of Q1, and that will also ensure a minimum time period regardless what position R1 is in.

You're going to get considerable sparking on the TURBO Relay contacts, so consider (a) a chunky Relay, and (b) some kind of surpression across the contacts (that's also a good idea on the GO Relay contacts) as the extra energy should be dissipated somewhere other than in wearing away the contacts.

Whoa No... there's a problem...

The Time-Delay Power for it's Relay (via the Parental Control Switch) is OK to be wired where it is (permanent 12v), but the Feed for R1 should be connected to Pin 1 of the GO Relay, so timing commences only AFTER the vehicle is already in motion. You're going to have to adjust your Zener and component values accordingly as that part is being fed from a 6v Supply.