395Views4Replies

Author Options:

3 volt signal to trigger 7 volt? Answered

Ok,so I get a 3 volt signal from a detector and use this 3 volt to trigger an alarm which atleast need a decent 7 volts to function.The detector could take a max. of 5 volts input which I got from the 7 volts DC supply.This 5 volts fed,gets transformed into 3 volts after the detection.So let me make this clear,I have a 3 volt and a 7 volt supply.I need to use this 3 volt to trigger the 7 volt circuit.I know what you are thinking-a relay !right?but I couldn't get  a 3 volt relay anywhere(though I got a 5 volt relay).I can tackle this situation in two ways.1)Either by stepping this 3 volt to 5 volts and making the relay do the job.but how? 2)Or some circuit to use this 3 volt to trigger the 7 volts(like a relay but maybe by using ic's).This is the final part of my project and so please help me.

Discussions

The forums are retiring in 2021 and are now closed for new topics and comments.
0
steveastrouk
steveastrouk

Best Answer 7 years ago

What current do you need to switch ? You use a transistor to amplify your 3V effectively.

0
Adarsh_tronix
Adarsh_tronix

Answer 7 years ago

hey steveastrouk!I think atleast 0.15 amperes is needed for the relay.But please do tell me which transistor to use...

0
steveastrouk
steveastrouk

Answer 7 years ago

Try a TIP 121, or a TIP32. They're darlington transistors and can switch quite a good load.

0
quatch
quatch

7 years ago

if it isn't high amps, use an optocoupler? A transistor could probably also do the job.