Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

relays

Status
Not open for further replies.

jazzyboydc

New Member
Hi I am new to this forum but I have a question. I am building a simple relay circuit. My source power is AC and I want to switch a DC circuit on when the AC circuit is on. Keeping in mind the requirements of voltage and amperage requirements of relays, do I need anything else besides resistors and the required wiring to hook up the relay. Do i need anything else? Can I mix ac and dc power circuits in a relay without a problem? because last thing I would want is to fry a relay I just bought or start a electrical fire or who knows what other danger is involved. Also what requirements do I need to keep in mind when shopping for a relay for my relay circuit
 

duffy

Well-Known Member
You can certainly drive a DC device through the contacts of an AC coil-type relay, if that's what you're asking. It's just a switch.

A solid-state relay is different. Those may only switch DC or AC, one's usually got a MOSFET, the other's usually a TRIAC.

Need to post the circuit before we can tell much else about it, though.
 
Last edited:

killivolt

Well-Known Member
Hi I am new to this forum but I have a question. I am building a simple relay circuit. My source power is AC and I want to switch a DC circuit on when the AC circuit is on. Keeping in mind the requirements of voltage and amperage requirements of relays, do I need anything else besides resistors and the required wiring to hook up the relay. Do i need anything else? Can I mix ac and dc power circuits in a relay without a problem? because last thing I would want is to fry a relay I just bought or start a electrical fire or who knows what other danger is involved. Also what requirements do I need to keep in mind when shopping for a relay for my relay circuit

You can it's just how you do it. Just watch your ineeez and outeeeez.

Put an ear to my post on ( I need a relay )

I hope you see and maybe understand.

Blind leading the Blind.

kv

Keep in mind the Dc circuit is awkward and way to different an animal. For that end you'll need alot of help.

Ok, what he said. Get a diagram.
 
Last edited:

RODALCO

Well-Known Member
To break DC voltage and current you need to have the relay contacts rated at the dc current in the circuit.

It is harder to break dc and arcing wears the contacts out quicker. Of course it depends weather you switching large currents or just a couple of 100 mA's.

The beauty of a relay is that it gives galvanic isolation between the control circuit and the switched circuit.

In the electrical industry we use 110 volt dc relays to switch 33,000 and 110,000 Volts circuits.

An ac relay can switch dc and vice versa.

Success with your experiment.
 

rskumar89

New Member
take a note of this !!

Just don't forget to buy a diode to keep it in shunt with the coil...
So that there is no backfire in your coil ...
 

Mike_2545

Super Moderator
Rskumar89, He is running the COIL with Ac not DC. If it were the other was round you would have given good advice. In this case, diode across coil = "Bad Idea"
 
Status
Not open for further replies.

Latest threads

EE World Online Articles

Loading
Top