Preferred relays? Relay power circuit?

[Funkalicousgroove]

Are You guys after an "Actual" Dumble circuit or just a way to make it work?

[pedro]

works Ok as is , but would really like to see and know the "right" way to do it funk.

Pete

[Funkalicousgroove]

Dumble changed it many times over the years, but the power supply described in the "ODS Notes" described a 12V transformer, full wave bridge rectified, into a 1000uf decoupling cap, an NTE 966 3 pin 12v regulator, and then another 1000uf decoupling cap. that b+ supply is then split 3 ways: 1 goes to the + side of both relays, the other 2 each go through a 1K resistor to supply the LED's. Some amps used a 4 pin XLR, some amps used a 5 pin DIN connector for the footswitch. so there should be 5 leads total: 2 relay ground leads(Before the manual/pedal switches), 2 LED supply leads, and a ground lead. The footswitch consists of 2 dpdt footswitches, 2 LED's, and 2 .02uf snubbers across the relay side of each switch to keep them from popping. There is a schematic for this footswitch on blueguitar.org, you just have to dig for it.

[Robert]

Funk,

If there are 5 wires going to the connector, how would one wire the 4pin XLR?

What is the difference/advantage to an XLR versus a DIN connector?

Thanks for your help.

[glasman]

Funk,

If there are 5 wires going to the connector, how would one wire the 4pin XLR?

What is the difference/advantage to an XLR versus a DIN connector?

Thanks for your help.

Usually there is a ground connection for the hood, I use this as my return . 4pins + hood connection.

I prefer XLR, they are more rugged and easier to work with than DIN connections. Albeit, they are a bit more money. But you should never have a failure. They also don't melt when you are soldering them.

Neutrik has a HUGE selection from 2 pins up to 7 as I remember. Check mouser.

Gary

[Funkalicousgroove]

I'm with Gary!

The XLR is rugged and easy to work with, I actually use a 5 pin XLR so that the whole circuit is isolated. Here is the catalog for the actual switchcraft part-

[BobW]

FWIW, If you just want a working relay circuit, check out my relay circuit it was cheap and quick and works well runnig from the heaters. It's in the LAYOUT section. BobW

[Bob-I]

FWIW, If you just want a working relay circuit, check out my relay circuit it was cheap and quick and works well runnig from the heaters. It's in the LAYOUT section. BobW

Bob... I've been looking for this but can't find it.

My relay ckt works fine with one relay, but with 2 it somehow acts as a voltage divider so each relay only sees 3.3V.

If I'm not crazy, parallel resistors see the same voltage but divide the current. I expected that this would relate to the relay coils and each coil would see the 6.6V that the power supply puts out.

Confused.

[Bob-I]

Ok, I got the relays working. I moved the supply line to the second relay. I'm not sure why but it's working now just fine.

[glasman]

Ok, I got the relays working. I moved the supply line to the second relay. I'm not sure why but it's working now just fine.

The problem was probably due to the 150 ohm resistor. The more coil current (ie two relays) the higher the voltage drop across the resistor. A cheap 1amp regulator would solve that problem.

Gary

[Bob-I]

Ok, I got the relays working. I moved the supply line to the second relay. I'm not sure why but it's working now just fine.

The problem was probably due to the 150 ohm resistor. The more coil current (ie two relays) the higher the voltage drop across the resistor. A cheap 1amp regulator would solve that problem.

Gary

Sorry Gary, that's not it. The voltage drop across that resistor was only about .3V but the 6.6V was divided exactly across the 2 relays, 3.3V each acting like a voltage divider ckt.

[BobW]

Bob, If you only had a .3 volt drop across the 150 Ohm resistor, then you only had (.3 V / 150 Ohms) = 2mA of current available. Assuming both coils draw the same amount of current means you were supplying 1mA to each coil. They were current starved. I don't know the specs of your coils but understood one coil operated OK at 2mA. So if you reduce your 150 Ohm resistor to supply a total of 4mA + 2mA as a margin, you initial ckt should work. hth

[BobW]

Forgot to mention my layout is in the FORUM under Dumble Files, under the TOPIC Layouts, about the 11th post down. This layout doesn't show the missing 4M7 resistor at the Mid Boost.

[BobW]

Bob-I, Did you ever reduce you 150 Ohm to a lower value so you wouldn't need to rewire your second relay to the supply line? just wondering. BobW

[Bob-I]

Bob-I, Did you ever reduce you 150 Ohm to a lower value so you wouldn't need to rewire your second relay to the supply line? just wondering. BobW

No, it works fine as it is. I didn't feel a change is necessary.