Flasher circuit using a BD679

[EddyCurrent]

Bruce,

This is the drawing for mine, just checked it at the machine itself.

[ozspeedway]

Thanks Eddy, looks just like what my version is. I now suspect our differences come from you using an ethernet smoothstepper and me using a parallel port. I have a strong suspicion that the PC is filtering some voltage via the P/port that the BD679 is seeing. I can confirm that by taking the p/port cable off the BOB and the LED goes out. Of course I can't then test Pin 14 out. However, an ESS is in my immediate future (next week some time) so I will see if my gut feeling is correct.

Cheers
Bruce

[EddyCurrent]

I've just had a look at the PMDX manual, it looks like you should be using pin 14 or 16 of J8 and JP3 should be set to 'outputs enabled', that's what it looks like after a quick read anyway. The outputs have an LED so it should be easy to see the state of your chosen output. I can't see the ESS making any difference so I would disconnect the flasher and concentrate on getting your bob output to go on and off from the software and not using the Brain function. When you get the output to operate correctly then connect the flasher and it should go on and off with the output. Now bring the Brain into operation and provided the logic is okay the flasher should operate.
It may be that the lamp is dim because it's being switched at high speed, try a multimeter with frequency range across the lamp.

[Wobbin]

What's the 'brain' function then ? Forgive what may be a dumb question, as I said I'm new to CNC...

[EddyCurrent]

What's the 'brain' function then ? Forgive what may be a dumb question, as I said I'm new to CNC...

This is the info that Bruce is using for his machine, see the Zip file attachment for the Brains.
http://www.mycncuk.com/threads/6565-...2213#post52213

Brains are a feature of Mach3 software, you can get an overview here;

[JAZZCNC]

I had an issue with a PMDX A few months ago with prox switches on Home switches (Inputs) not being pulled to ground and the cure was a small resisistor between ground and the pin. It sounds like you are having a similiar thing so worth a try.?

[ozspeedway]

Jazz... close I think.....

It is now working after receiving an email from Steve @ PMDX. In his email he indicated that I needed to connect the negative from the 24v supply to GND so the transistor had a reference to it. I did that and it works. I now know why Eddy's worked from the start (at least I think I do), his BOB is powered by the same 24v supply as the flasher circuit and therefore the tx already had a reference to the 24v neg side. I am thinking now if I replaced the 24V LED with one suited more to 5v whether it would work without grounding to the supply. However, that would probably be a moot point given that I have a PMDX 126 winging its way to me as we speak and it is powered by 240v.....

Thanks to everyone who ran around in circles with this, I really appreciate the help given

Cheers
Bruce