3 way footswitch.

[norburybrook]

I'm thinking of replacing my BM that was prized from my hands last year.

After building the 2nd gen and putting the FET in the front on a relay, I was thinking about doing the same again.


My question is then; can I power three relays from the standard rectifier board, and how is the footswitch wired?

with two relays I can see with the 5 way socket there's a ground then a feed to each relay and to the power board. Can I just add another 1k resistor to the node from the 1000uf 50v cap on the rectifier board? would I need to then use a 7 pin din and 7 stranded cable for the footswitch?


Marcus

[Charlie Wilson]

You can remove the 1k resistors on the board and put a jumper. Then run the LED voltage on one pin of your footswitch receptacle to your footswitch LEDs and jumper across them. Then you can put the 1k(or appropriate value for type of LED) limiting resistors on the ground side of the LEDs in the footswitch. That way you don't need a 7-pin receptacle.
CW

[norburybrook]

thanks Charlie. I've inherited a footswitch that has a 7 pin din so I might as well as well keep it that way as a 7 pin din for the amp costs the same as a 5. Also flexible CAT5 cable has enough strands and is cheaper than the start quad cable I've been using for the 5 pin dual footswitches, so it will be cheaper to do it that way. I'm making my boards so making and extra eyelet is no problem.

That's it then...I'm not building any more amps..................this is the last one.....



M

[norburybrook]

You can remove the 1k resistors on the board and put a jumper. Then run the LED voltage on one pin of your footswitch receptacle to your footswitch LEDs and jumper across them. Then you can put the 1k(or appropriate value for type of LED) limiting resistors on the ground side of the LEDs in the footswitch. That way you don't need a 7-pin receptacle.
CW

Charlie,

I've been thinking about this and opened up my footswitch today. It's wired how you suggested. There's a 7 pin DIN on there but only 5 connections used.
Also with this on mind I realise there will be less wire in the amp too doing it this way, especially as there will be 3 footswitches/relays. I would have three separate runs to the footswitch jack if I did it the 'old' way. Your way there's just one, and only 1 pin required on the footswitch socket/cable instead of 3

Thanks for the heads up on this I'm going to do it your way as it seems a lot simpler/ergonomic solution actually.

Marcus

[norburybrook]

what current do 3 12v relays draw. I'm just looking into cable choices fro the footswitch and I can see there are a lot of options a lot less expensive than high end start quad cable I've been using.

Is there any advantage in using 'thick' heavy 6A cable other than the obvious durability issues fro stage use.

You can buy shielded 8 strand alarm cable rated at 1A for peanuts.


M

[martin manning]

Depends on the relay, but something like 15-40 mA. The larger current could be the 3 LED’s on one wire, as much as 30 mA each (if you run them at rated current). The standard setup with red LED's and 1k current limiting resistors will use about 10 mA each. A standard 5-pin MIDI cable is a good option, and the wire is easily big enough to handle the current. Another advantage is that it is easy to find a ready-made replacement.