Continue to Site

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.

How to Convert 4.5V AC to 2.3V AC?

Status
Not open for further replies.
A transformer with a turns ratio of 2:1 should do the trick.
 
Hi,
i already use a tranformer to convert 240 V AC to 4.5V AC .since i cant find a transformer to reduce to 2.3 V,
i want any other methods to reduce the voltage to 2.3 V AC
 
Why do you want 2.3vac? Kind of an unusual request. There are ways to do this but we need to know the app.
 
The application is for the mesurement of 240V AC using the PDA. the card used in PDA supports only upto 5V. So i want to bring down the voltage. i have tranformer which converts 240 V to 4.5 V
 
What is it that you want to do?
Measure the amplitude of the 240vac or use the period as a clock for something?
If it's the amplitude use a resistive divider like akg already said.
If it's the period I know optocouplers that can be connected directly to 240vac, so no transformer at all.
 
this means take two resistors (in your case same value since you want to split input voltage to two equal parts). you can try 2x 1kOhm resistors. connect one end of each resistor to your PDA or whatever. connect other side of first resistor to one end of the transformer's secondary. connect remaining lead of second resistor to the other end of the secondary and to your PDA.
 
The peak voltage for 240V Ac is close to 320, 240 being .77 of the peak.
A transformer won't give a accurate indication of the 240V supply as the transformer is a big inductor.. Try a ferrite ring with a gap cut in and a few turns of wire on the ring.
 
Last edited by a moderator:
I'd be really careful about an opto on 240VAC mains. Would you care to compute the power disipated in the resistive divider or in the LED stage of the optoisolator. I think you will be amazed at how the required LED current wil fry the resistors.

I agree with the other posters who caution you on connecting 2.3VAC to the PDA. The likely result will be a fried input.

You can of course use the 4.5VAC output of your transformer with an optoisolator to detect the presence of the 240VAC or even measure it's frequency.

Tell us again, are you interested in the voltage or the frequency of the 240VAC mains?
 
Last edited:
Papabravo said:
I'd be really careful about an opto on 240VAC mains. Would you care to compute the power disipated in the resistive divider or in the LED stage of the optoisolator. I think you will be amazed at how the required LED current wil fry the resistors.
I don't if you use a HCPL-3700. It's rated 5 to 240V ac/dc sensing voltage so no problem ;)


Papabravo said:
Tell us again, are you interested in the voltage or the frequency of the 240VAC mains?
Absolutely, we still don't know what anishkjohn want to do with his PDA.
 
What does the HCPL-3700 cost compared to a 4N25 or a PS2501?
 
Why the focus on the frequency, if that was all that needed most cards require or can withstand a 5V transition, the fact he trying to produce a voltage appox 1/2 of 5V would suggest to most people that have built ADC
running from a 5V supply that the amplitude of the signal was of concern. I know PDAs run on all ranges of voltage, mine wants 3.6V. If the amplitude is wanted then the ADC input has to deal with 650V P-P not including spikes from switches motors etc.
 
We ask the question because the answer changes the requirements, and thus the set of possible solutions. I would never presume to know such an answer in the absence of a definitive statement. My extrasensory powers just ain't what they used to be.

LOL
 
anishkjohn hasn't joined in the group for 4 days, do they care about our musings anymore?
 
Status
Not open for further replies.

Latest threads

New Articles From Microcontroller Tips

Back
Top