GM20s

[Laserman532]

DZ...Thank you for posting your findings and designs on this thread. Greatly appreciated.

OBTW - BUMPED for the "3 Left" Announcement

[danielbriggs]

DZ/Buffo/Pat,
Looking at that circuit diagram, could I stick in 1N4001's, and a 47µF tantalum cap instead?
Mean's I've gorra go t'shop if not.

Is this the right tranny? Looks a bit small... http://uk.rs-online.com/web/search/s...duct&R=0295028

And is this thee right relay?
http://uk.rs-online.com/web/search/s...duct&R=4936458

Sorry to sound like a nagging bugger... electronics RELAY isn't my forté
...it's been one of those days...

[DZ]

Yes, that transistor will work and that relay will work. The 1N4001 will work just fine, I always use 1N4007's since I have about 3000 of them... 47uF will probably be fine, just depends, use it and it if seems too slow, then go with a lower value.

[danielbriggs]

Ta muchly DZ.
I have loads of lower capacitance ones, but they're all electrolytic.

Dan

[DZ]

The electrolytics will work just fine too!

[MechEng3]

This was sent to me from Bill. Works great...and you could vary the power to the load a bit. Plus is that the local rip-off shak will have the goods on hand.

[Laserman532]

Yeah, That little circuit shouldnt cost more than 30 or 40 dollars at ripoff shaque.


BUMP- "2 Kits" left.

[mixedgas]

This was sent to me from Bill. Works great...and you could vary the power to the load a bit. Plus is that the local rip-off shak will have the goods on hand.

I'd like a reverse diode across the GM20, and I put a 20-40 ohm resistor across the GM20 for damping.

Steve

[Banthai]

MechEng3 said

This was sent to me from Bill. Works great...and you could vary the power to the load a bit.

Well if bill sent you that... he needs a slap on the back of the hand and be forced to eat a big bowl of Lasorbs for breakfast every day for the next 6 months

Both Sides of the GM20 are being driven by the 0v rail so it will never operate

also the 2n2222 transistor has a collector current of 800ma max so best to use a TIP120 as reccomended in mechs drawing

i also use a similar circuit but with an opto isolator prior to the base resistor to isolate the 5v and 10v

I think your drawing should look like this ... but even i could be wrong

all the best ... Karl

[MechEng3]

Thanks Karl...but it was meant to be a very easy and quick solution. Something that could be "dead bugged" and placed in use. Guess I will regress to using Pat B's method....it may be fault proof....no caps or opto-isolators.