Triac power problem

[angel-tech]

so you should have the 0-10v variable voltage on 4 and 6, with 4 being positive. If you're not getting any voltage on 4 and 6 and you've specified a speed and commanded a spindle start on the triac, this will probably be the fault. Pin 5 should have a reference voltage on it, so check across 5 and 6 for 10v. If you get 10v across 5 and 6, remove the wires from 4 and 6 and connect 4 and 5 together, then you should get full speed when you command a spindle start.

Again be careful here as the 0v of the 0-10v is not connected to ground.

[PDodds]

Hi,

I have been out and tested for those voltages.

I have no variable 0-10Vdc between 4 and 6.

There is also nothing between 5 and 6, so I presume that the reference voltage is missing, and thus causing the fault?

Is this voltage fused somewhere?

Thanks again
Paul

[Denford Admin]

You could always fit a potentiometer to the 3 connections (I'm sure the manual I referred to earlier shows the speed input as a pot)
Then you'll know for sure that's the issue.

[PDodds]

I had thought about a pot, but if the reference voltage is not there, surely that wont work?

thanks
Paul

[Denford Admin]

Ah yes sorry - I hadn't seen you mention the reference voltage was missing.
I'd certainly expect 10V between two of the speed input pins (5 and 6, Lo and Hi according to the B&P manual)

Try it again with the wires disconnected from 4,5 and 6...

[PDodds]

Ok,
I have tested the voltages with the wires disconnected, and between pins 4 and 5 I get approximately 7.8Vdc when spindle speed was set at 1000rpm. It then steadily decreased until the machine faulted out.
When I connect the wires back on, the voltage is not there.
I am guessing that this is what you expected to happen?
Any ideas why?
Here is a pic of the terminals on the fanning strip.
I really appreciate the help guys

[angel-tech]

there is one other thing to try on the fanning strip.

You can manually run the spindle by removing the wires from 4, 6, 7, 8 and 9.

Then get a PP3 9v battery and connect it up to 4 (+) and 6 (-). and take 8 and 9 to a switch. Turn on the triac and close the switch, this should give you near full speed.

PS. have you removed the jumper wire you put on the main contact strip.?

[PDodds]

Hi angel-tech,

Thanks for the reply.

I have just tried that, and still nothing at all. Does tis mean that I need to look for a replacement Brown&Pestell drive because this one is caput?

Cheers
Paul

[angel-tech]

one of these will do

https://www.ebay.co.uk/itm/380382624135? ... 1438.l2649