Relay supply

[heisthl]

Thanks for the enlightening discussion above.

I'm still confused about my drawing with the series resistor and LED...

Looking at the diagram, the switches on the left are panel switches on the chassis, and the ones on the right are foot switches.

It seems like all the foot switches would do is turn on the LED (provided the panel switch is on), without switching the relay.

When you press the footswitch the ground current passes through the LED/resistor(LED lights up) and continues on to activate the relay.

So, question... Are the footswitches supposed to be DPDT switches, with one pole operating the LED and the other pole shorting the (-) relay terminal to ground?

The beauty of this design is the cheaper single pole switch can be used.

According to HAD, is the LED supposed to be ON in OD mode and in PAB mode? If the LED should be OFF in those modes, then couldn't I just put ground in the center lug of the foot switch, with the LED circuit being on one side of the throw and the (-) side of the relay coil being on the other side?

Again, still trying to understand this stuff...

Thanks

On a real one the LED comes on when the relay is activated (i.e. OD on means OD LED is on too). HAD only used 2 footswitches OD and Boost and on the pictures I've seen used all 5 wires for them. 1 ground, 2 LED supplies, and 2 paths for grounding the relays.

[HiGain]

The beauty of this design is the cheaper single pole switch can be used.

Thanks for sharing... Just so I know, was this HAD's design or is something you designed?

And, as a related question, did HAD use a SPDT footswitch or a DPDT one?

Thanks very much!!

Jake

[ayan]

The beauty of this design is the cheaper single pole switch can be used.

Well, all designs I have ever seen can be implemented with a SPST switch. The only time that is not possible is if you want to have dual color LEDs, like red = lead and green = rhtyhm, for example.

Gil

[heisthl]

The beauty of this design is the cheaper single pole switch can be used.

Thanks for sharing... Just so I know, was this HAD's design or is something you designed?

And, as a related question, did HAD use a SPDT footswitch or a DPDT one?

Thanks very much!!

Jake

If this was a HAD design it would require 9 wires!

[Bob-I]

First off, the regulator is not really necessary. The bridge/filter should give you close enough for a relay, which will activate with low or slightly high voltage.

Second, the series resistor on the LED isn't really required. The relay coil will act as this series resistor. IME using the series resistor the relay trigger gets intermittant as the resistor can drop voltage required for the relay.

All that said, I'm having some trouble with a 5V ckt. I used the rectifier supply on one of my amps and it works fine, unless I connect the LED's, then I can't get the relay to trigger.

Any thoughts on that one?

[drz400]

First off, the regulator is not really necessary. The bridge/filter should give you close enough for a relay, which will activate with low or slightly high voltage.

Second, the series resistor on the LED isn't really required. The relay coil will act as this series resistor. IME using the series resistor the relay trigger gets intermittant as the resistor can drop voltage required for the relay.

All that said, I'm having some trouble with a 5V ckt. I used the rectifier supply on one of my amps and it works fine, unless I connect the LED's, then I can't get the relay to trigger.

Any thoughts on that one?

You are loosing voltage oing in series with the LED (Diode), sounds like too much or you are on the edge to throw the relay. especially with 5 V you are loosing 1.2V about.
It is much better to use a transistor to drive the relay and you can put the LED/resistor across the switch to lite up in reverse mode. You can also use CMOS to be a buffer which drives the transistor and relay. This way a series LED is absolutely no problem

PS unregulated relay supplies can inject noise into the audio section of the relay especially if they are not shielded from the coil.

[ayan]

First off, the regulator is not really necessary. The bridge/filter should give you close enough for a relay, which will activate with low or slightly high voltage.

Second, the series resistor on the LED isn't really required. The relay coil will act as this series resistor. IME using the series resistor the relay trigger gets intermittant as the resistor can drop voltage required for the relay.

All that said, I'm having some trouble with a 5V ckt. I used the rectifier supply on one of my amps and it works fine, unless I connect the LED's, then I can't get the relay to trigger.

Any thoughts on that one?

The regulation is not needed to get the relay to operate and well. However, transients in the coil if the supply is not very steady could find their way into the audio path. Dumble even went through the trouble to run a separate ground for the relays for similar reasons, I presume.

On your 5V project, I am not sure how much juice you're feeding the LED or what the circuit looks like, but it seems as though after all is said and done you are ending up with not enough current through the relay coil to evergize it. The method that always works is to have the LED on when the relay is not energized, as used by Mesa/Boogie (which I already mentioned above.

If you'll post a schematic, I will be glad to look it over.

Gil

[HiGain]

OK... this is the only way I can imagine using a SPDT footswitch with the series Resistor>LED method used by HAD.

ODand LED comes on when relay is in OFF mode. Same with other functions.

As far as I can see, for the functions and the LED to come on when relay is turned on, you would need a DPDT footswitch.

So, can someone please tell me if I am right and if this was HADs system. I'm just trying to understand.

In the end I may use heisthl's system becuase of how my amps are wired. But I still want to UNDERSTAND!

Thanks all.

[Fischerman]

Looking at these schematics posted I'm seeing an LED illuminate when in OD but where's the LED for Clean? I want to have one (probably red or orange) LED illuminate when in OD and another (probably green or blue) illuminate when in Clean (and I obv want the 'other' LED to extinguish). I don't even need any LEDs for anything else.

The way I had planned on doing it (after a suggestion by heisthl in another thread) was to have one LED/resistor in series with the single-button footswitch (which is also in parallel with a SPST pull-pot on the Clean Master)...and another in parallel with those switches. I would need two different resistor values (and possibly two different 'illumination' LEDs...i.e. maybe one bright one regular). I'm sure this will be a bit of an adventure but I'll probably learn a lot along the way.

Question: for those that are having chattering problems or ringing or whatever...would using extra bright LEDs help alleviate this problem?

Still, just curious if I'm missing something or do you guys usually have separate LEDs for Clean and OD?

[HiGain]

OK... My brain kicked in. I didn't consider connecting the (-) relay terminal and cathode of LED from the LED-Resitor-V+ string. I asked over at ampage if that was OK to do if these nodes are ungrounded.

Looking back, I think this is what Gil told me to do!

Here's another version, which is more simple. It moves the bright switch to the footswitch (an idea floated here by someone else...can't remember who), allowing the bright to be toggled on automatically with the clean channel only.

Fisherman, regarding your question about additional LEDs for the OFF states, e.g. clean mode. If you wire your footswitch so that the center lug is ground, wire your ON LED to the side of the switch that engages OD, PAB, etc. and wire another LED-Resistor to the other side of the switch. Stomping the switch will alternate between groundind the two LEDs.

Thanks for the help, everyone.

Jake