# Solid state step up voltage

Discussion in 'General Electronics Discussion' started by pidja105, Jan 5, 2016.

1. ### pidja105

106
1
Oct 16, 2015
Hello,
I am making very small wattage power inverter for some tests(1.2W) with relay with 4 terminals, yes i successfuly convertered dc to ac but voltage goes down(from 12 to 2V).I have a transformer for 12V but if I plug into transformer 2V on output i have 44V.My question is how to step 2 to 12 V without using transformers or capacitors?

2. ### Harald KappModeratorModerator

10,593
2,364
Nov 17, 2011
You wil need a boost converter. You will require an inductor, however.

Show us your circuit diagram so we can understand what you do.

3. ### pidja105

106
1
Oct 16, 2015
Here you are!

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4. ### Harald KappModeratorModerator

10,593
2,364
Nov 17, 2011
Can you please explain how this is supposed to work?
Assuming the circuit can be made to work, it will not last very long. A good relay is rated for e.g. 10*10^6 operations (at 6...1200 operations per minute). Assuming the fastest operation you have 1200 operations per minute which equals 20 operations per second. At 10*10^6 operations lifetime this corresponds to 500000 seconds lifetime = 138 hours lifetime = 5.8 days. After 5.8 days the circuit will become unreliable and is prone to fail. If you want any useful lifetime from a step-up converter you'll have to use semiconductor switches aka transistors, see the link in post #2.

5. ### Osmium

67
17
Jan 28, 2013
Harald, it comes from this wikihow page: http://www.wikihow.com/Convert-DC-Power-to-AC-Power

The missing piece of info is that the relay contacts shown are normally closed. Remember vibrator power supplies in old valve car radios? (oh... crap... yes I am that old...). The vibrator worked essentially like this.

To the OP: It might help if you tell us what you are trying to do overall. From what you've said so far, it sounds like you want to convert DC 12v to AC 12v, yes? And what you've used so far is very old technology - which is OK if that's what you want to play with.

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