Switching On/off 240v Via 26vdc

[nickk1]

Hi
First post my electronic no how is close to zero so can any one help.
I have a 240v feed which I need to switch via max 26vdc is there a way I can do this amps would be 20 A max?
Nick

 

[Nigel Goodwin]

A simple relay?.

 

[nickk1]

how would I wire it and what one, size make would I be looking for.
As I said no how limited.
Nick

 

[Nigel Goodwin]

You need to tell us exactly what you're switchig, and exactly what the control signal is.

 

[Cry_Wolf]

If you use a SPDT (Single Port Double Throw) It would have five connecting points, VDC , GND , NO , NC and C. When you apply voltage across VDC and GND , NO and C points become short otherwise NC and C are short.

So if you connect your connect your device through C and NO, It will work when you apply VDC to your relay.

And remember, to be on the safe end connect an appropriate diode across VDC and GND to avoid Back EMF
**broken link removed**

 

[nickk1]

What this is for is turning on and off a gas solanoid valve in a welder the valve is rated at 240v 50hz.Power going to the valve is 240v ac, I want to controle it i.e turn it on / trurn it off via the controle trigger in the tourch which gives out 26vdc this supply comes from a transformer. Sorry dont know what you mean by controle signal.
Nick

 

[Nigel Goodwin]

The 26V is the control signal, you mention it's DC, do you know what current it can provide?.

Presumably the 240V valve doesn't require a lot of current?, so you just need a 24V relay (24V is a standard voltage), and wire it as above.

 

[nickk1]

Please forgive my stupidity but do I use a 24v dc relay or a 240v ac one?
Nick

 

[Nigel Goodwin]

The relay 'coil' is 24V DC, the switching contacts are rated for 240V AC.

A relay is essentially a mechanical switch (the contacts) moved by an electromagnet (the coil).

 

[nickk1]

What size diode would i use to stop EMF?
NICK

 

[Nigel Goodwin]

What size diode would i use to stop EMF?
NICK

What makes you think you need one? - and a diode doesn't do that.

Like I asked before, what actually feeds this 26V?, and what is is supposed to feed?.

 

[nickk1]

Ciruit working thanks for all your help
Nick