Powerboard question

[erwin_ve]

. I have also changed the relay board, but still no reaction on the OD channel. Might be something wrong in the relay itself. Waiting for the new ones.

Did you put the relay on a socket or soldered it directly to the pcb? Sometimes these sockets fail when installing, remove and install the relay again.

[Oddvar R]

. I have also changed the relay board, but still no reaction on the OD channel. Might be something wrong in the relay itself. Waiting for the new ones.

Did you put the relay on a socket or soldered it directly to the pcb? Sometimes these sockets fail when installing, remove and install the relay again.

I did change the relay board, I think it's a Hoffman board, with two rows pinpoints. It's a good tip about the socket though. Maybe I should solder directly to the board.

I am trying to figure out the original Calrad relay, seems a bit different, no doubling of the clean sound and no ground, I have tried to get hold of one, but even Calrad themselves no anything about it.

I am not sure to be honest, what is being turned on and off with the relay. Seems simple, like a regular DPDT swicth, but I don't understand it. One set is active when th power is on and the other when the power is off. And maybe the relay I have is configured different than the one to use.

Pity though, everything else works, and the amp is very silent.

[martin manning]

You can check the relay function with your multimeter by making sure that when OD is off, Com and NC are shorted, the OD input is grounded, and the clean output goes to the level pot. When OD is on, Com and NO should be shorted, OD input is connected to clean output (and not grounded), and OD output connects to the Level pot.

[Oddvar R]

Great tip, I will do that. When you say shorted, what do mean? (Voltage or ohm?) Remember, I am Norwgian.

[erwin_ve]

. I have also changed the relay board, but still no reaction on the OD channel. Might be something wrong in the relay itself. Waiting for the new ones.

Did you put the relay on a socket or soldered it directly to the pcb? Sometimes these sockets fail when installing, remove and install the relay again.

I am not sure to be honest, what is being turned on and off with the relay. Seems simple, like a regular DPDT swicth, but I don't understand it. One set is active when th power is on and the other when the power is off. And maybe the relay I have is configured different than the one to use.

Maybe this is helpful in understanding how a relay is switched:

[martin manning]

Great tip, I will do that. When you say shorted, what do mean? (Voltage or ohm?) Remember, I am Norwgian.

Ohms approximately zero between those contacts.

[Oddvar R]

I tested the relay and the ohm between the pins where present C-NC was 0.6 Ohm and C-No was 2m and 2m aprox.

[pompeiisneaks]

and when you flip the switch on the panel do you see that change?

Another test you could do would be do connect one end of the multimeter to the expected end of the circuit for the relay's power, and then connect to the side that's being switched of the relay coil. Then flip the switch on the panel to see if you toggle between open and near 0 resistance. Basically you should first confirm that the panel switch and/or the footswitch can trigger that 12V relay's coil, i.e. you see the 12v circuit closing into an actual circuit.

~Phil

[Oddvar R]

That tip was great, because in checking that I found that when I short the upper pin of the Manual switch to the chassis tip of the switch itself, the OD pot works, why is that?

[martin manning]

My guess is you are grounding the relay coil and energizing it. Once again, with the panel switch set for OD, are both NO contacts shorted to their respective Commons? In addition, the Clean out should be connected to OD in, and the OD out connected to the Level pot through the relay, so you should have continuity between those points. If not, you have a wiring error or possibly a faulty switch.

[pompeiisneaks]

To try and super over simplify it. The relays work on a very simple principle. Ignore the actual 'switching' part. What matters is how the 'switch' itself is flipped. Normally you use your finger and a physical switch. In this case imagine you're putting a 12V battery to to contacts making a circuit and it flips the switch. If you remove the battery, the switch goes back to where it was. the connections on the other side of the relay are like any DPDT switch itself, but instead of a physical button/toggle/baton, you have no physical button, you put 12V to the coil. Since you did something to short the 12V to ground that closed the circuit and proved the relay is working and the switch seems 'right' what it does mean is that something in the path from the relay through the panel switch and/or the footswitch is wrong, and no longer allows you to 'ground' the circuit, or close it out.

~Phil

[Oddvar R]

My guess is you are grounding the relay coil and energizing it. Once again, with the panel switch set for OD, are both NO contacts shorted to their respective Commons? In addition, the Clean out should be connected to OD in, and the OD out connected to the Level pot through the relay, so you should have continuity between those points. If not, you have a wiring error or possibly a faulty switch.

When I measure the ohming from COM1/2 to either NO1/2 or NC1/2 I get 0.6Oh, an 1M ohm and 2mOhm. When I short the switch the ohming on COM to NO1/2 goes to aprox zero.

[martin manning]

So the relay seems to be working correctly if you manually ground the negative side of the coil. Looks like the layout is missing a ground. I would correct that as shown below, taking all relay and footswitch grounds to the regulator's center pin.

[Oddvar R]

That seems to be working. Thank you. That was a steep learning process.

[martin manning]

Great! All good now, or are there more of Loki's children to chase down?