I'm looking to read the frequency of a 6v ac signal for zero crossing from what i understand i can get away with a from ra4 to vdd and a 100r from 6vac to ra4 then i just use timer0?
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I'm looking to read the frequency of a 6v ac signal for zero crossing from what i understand i can get away with a from ra4 to vdd and a 100r from 6vac to ra4 then i just use timer0?
Yup but 100 Ohm is probably too low. 6 Vac gives about 9Volts in Peak. 9/100=90ma... i'll prefer to use something like an 1K.
Probably the following post i did few times ago can help. It's a simple frequency counter.
http://www.picbasic.co.uk/forum/showthread.php?t=1044
Quote:
Originally Posted by mister_e
Cool thanks, i noticed you simply used a 1k on the in and a 10k to ground?
basically i'm using a 6v peak to peak 60hz signal just need zero crossing
that's different, so you don't need any timer stuff. Just poll the pin or use Interrupt on X pin on rising or falling edge.
The following is another one wich can be handy.
http://www.picbasic.co.uk/forum/show...63&postcount=5
OR on Melabs website wich also include the schematic. Dimmer.Zip
http://www.melabs.com/resources/samples.htm#submitted
*** EDIT ***
Yeah on the previous i lace 10K to ground to avoid weird reading when the input is left open. That way it ensure the PIC see 0V so never count and display XYZ results.
Ok that one's using rectified ac not a problem thats where i was gonna grab my 6v, r1 is not listed but will drop in a 1k, i noticed there were no snubbers on the triac but that was for a resistive load here's what i was thinking
http://www.chrisncarol.com/switch.jpg
Quote:
Originally Posted by mister_e
Yup even if the snubber method is recommend, ST do some Snubberness one. I actually test them running few 10 AMP inductive load without any snubber. As now, since 2 weeks, no problem, no fire, no temperature raising seems quite stable... as now
Look the datasheet
http://www.st.com/stonline/books/pdf/docs/7470.pdf
Anybody else here already tried and got success with those St Snubberness BTA/BTB series without snubber??
Hello Steve,
Yes, I am using thousands of ST Snubberless Triacs in Traffic control systems, they drive 230/10 volt transformers for halogen lamps up to 5 amps, they are running 24 hours, continuous switching for about 5 years till now, the maintenance records don't show more than 5 Triacs faults in more than 150 traffic controller each has (30-60) Triac.
Regards
Mohammed
thanks Mohammed for your reply. Glad to know they work As Is without any extra stuff.