Using the rj12s to put out 12v?


#1

Hey all,

I was wondering if it were possible to use the rj12 connectors to switch 12v relays. I know that the connectors can supply 5v or 12v to boards hardware-wise, but i was wondering if the brewpi software supported switching on the rj12s instead of the 5v digital outputs.

Dus anyone have any experience with this? Thanks!


#2

The RJ12 ports only have bus communication protocols on them. All of the signals go through driver IC’s, so it is not possible to switch digital signals directly.

To drive SSRs on RJ12, we have the OneWire SSR board, which can drive 2 SSRs:
https://store.brewpi.com/brewpi-onewire-ssr-expansion-board

If you want to switch 12V devices, for example a 12V heater, pump or SSR, the easiest way is to use a DC SSR:
https://store.brewpi.com/temperature-control/solid-state-relays-ssr/ssr-dc-10a

I don’t know what exactly you need to use 12V for. The 12V on the RJ12 connector can only supply ~1.5A.


#3

I want to switch 2 Hager ERL425SDC relais, they need 12 v dc. Can the OneWire SSR board do this?


#4

No, it seems that they require 12V to switch. You’d need a transistor too.

Our valve control board has an H-bridge to switch 12V ball valve motors, this could be used to drive the relays.

Why do you want to use these relays? If you want to use PWM, you will be cycling them quickly. They have a limited lifespan, the number of cycles is given in the spec sheet.