Calculate how many amps a solenoid needs

[The Master]

Thanx. That really clears a few things up. My new multimeter is pretty confusing at first glance and i was never shown how to use one properly in school :@

I just wondered where 8 came from. Im not sure about the total amount exactly yet but all that has to be arranged before designing the circuit anyway.

Yes, allowing a little extra is always a good idea. Im going to work it out asif all the solenoids are on at the same time. Realisticly i dont think that could ever happen but if a PIC chip goes wrong somewhere and turns them all on i dont want it to start smoking.

Just one more small question about the settings. When moving from 200ohms to 2K the decimal point moves. Is this just so the smaller numbers can be measured with greater precision?.

I have to remember that its measured in Kohms too. 1 = 1K and not 1ohm

[The Master]

Something else ive just thought of. Since im using an AC PSU and a rectifier i need a capacitor. Most of the solenoids are fine but the flipper solenoids buzz a bit because of DC ripple. In this case (or for any other circuit) how do i know what capacitor to use? Ive been told that 24uf is enough but i dont know where that figure came from. Is there a name for this type of equation?

[chuck]

it just means that you can measure higher values that's all, for your meter
Has for the cap the normal rule of thumb is 1000uF per amp, I think you would find that a 24uF would not last long. or it would not remove any ripple out of it at all

[The Master]

Thats what i thought. It seemed a really small value for solenoids. "1000uF per amp" thats easy to remember thanx!