relay for footswitch in HoSo 56

[CraigB]

I have no experience with switching relays at all, but I'd like to make the boost as shown on da Geezer's HoSo 56 schematic footswitchable using a DPDT relay.  My power tranny has a 27-0-27v tap that is unused, can that be used as the power source to power the relay?  Can anybody point me to schematics/layouts of what I'm after?   Thanks

[Fresh_Start]

Try the SEARCH function here and in the Library.  Doug's 18-Watt Stout uses a relay to switch a preamp stage in & out.  Maybe you can start with that.  Also, the "Solid State" section here may be a good source of info.

Sorry I don't know enough to answer your question.

Chip

[Geezer]

I cheated  :-[ ..... I used a Weber Relay board (low power).  $10 for the kit, or $14 assembled.

Here's the pic & description>>>
https://taweber.powweb.com/store/chansw.htm

Here's the catalog page>>>
https://taweber.powweb.com/store/chansword.htm

Doug sells the "raw" relays & has a good description of "how to" in "The Tube amp Library of information" link at the bottom of this page.

Here's a start>>>
http://www.el34world.com/projects/relay_switch.htm

[PRR]

> My power tranny has a 27-0-27v tap that is unused, can that be used as the power source to power the relay? 

Hoffman's relays are 5V at unspecified current. That's a big mismatch from your 27V-38VDC, and not enough data to suggest a simple kludge.

24VDC DPDT relays are readily available. Here's an 8mA job, four bucks, hundreds in stock.

www.mouser.com search on "G5A-237P-DC24"
G5A-237P-DC24 datasheet

Use Hoffman's plans, except change 4700uFd to 470uFd 50V, insert 1K between that cap and relay/LED node, change LED resistor to 4.7K.

[CraigB]

Thanks for the info guys - Craig