convert 110v dc to 24v dc

[elshorbagy01]

hello everyone, I need help
I have an instrument that works at 24v dc and I have only source of 110v dc
What can I do?

 

[Minder]

What is the nature and/or origin of the 110vdc?
M.

 

[elshorbagy01]

What is the nature and/or origin of the 110vdc?
M.

Batteries, but I can't divide it , I have only one cable of 110v

 

[Minder]

What is the max current requirement of the 24vdc?
M.

 

[elshorbagy01]

What is the max current requirement of the 24vdc?
M.

150 mA

 

[Minder]

I have done this with a simple resistor, 24v zener diode and electrolytic capacitor.
It was on a mobile crane generator that output 240vdc and I needed 12v or 24v for a regulator circuit.
This worked a treat.
You have to calculate the value of the series resistor for the max 24vdc load.
For 110vdc you will need a 12w 550 ohm ww resistor approximately, it is not the most elegant way, but uses the least components.
M.

 

[elshorbagy01]

I have done this with a simple resistor, 24v zener diode and electrolytic capacitor.
It was on a mobile crane generator that output 240vdc and I needed 12v or 24v for a regulator circuit.
This worked a treat.
You have to calculate the value of the series resistor for the max 24vdc load.
For 110vdc you will need a 12w 550 ohm ww resistor approximately, it is not the most elegant way, but uses the least components.
M.

may you draw that circuit

 

[Minder]

Place a 100uf capacitor across the 24v zener diode, V2.
M..

 

[elshorbagy01]

View attachment 26174
Place a 100uf capacitor across the 24v zener diode, V2.
M..

thank you,
and if you find another solution plz tell me

 

[duke37]

Many switch mode power supplies work on AC but the first thing they do is to rectify the AC to DC. They should be able to run on DC without modification.

 

[Colin Mitchell]

Where do you get 110v DC from ????

 

[cjdelphi]

You sure it's not wall 110ac voltage?

 

[elshorbagy01]

Where do you get 110v DC from ????

Batteries, but I can't divide it , I have only one cable of 110v

 

[elshorbagy01]

You sure it's not wall 110ac voltage?

Batteries, but I can't divide it , I have only one cable of 110v
And if i have Ac it will become easy by using transformer and rectifiers

 

[cjdelphi]

I'm thinking a resistor divider / zener as mentioned which powers a microprocessor then use a switching method to an inductor to buck covert it

Tricky

 

[elshorbagy01]

I'm thinking a resistor divider / zener as mentioned which powers a microprocessor then use a switching method to an inductor to buck covert it

Tricky

how to calculate the inductor and resistor to get 24v out of 110v

 

[duke37]

how to calculate the inductor and resistor to get 24v out of 110v

Making a switch mode supply is complicated and not for the novice.
Why not use a standard 110V to 24V switch mode supply (buck convertor) as I mentioned earier?

 

[elshorbagy01]

Making a switch mode supply is complicated and not for the novice.
Why not use a standard 110V to 24V switch mode supply (buck convertor) as I mentioned earier?

i searched for that and i didn't find that rating,
only max 40v dc buck convertor
if you find one plz tell me

 

[AnalogKid]

You can buy switching regulator modules that handle this input voltage range, or build one with a control chip fro Linear Technology.

ak

 

[duke37]

I found several on e-bay 100-240V in to 24V DC power supplies.
They specify 50 or 60 Hz input but I would expect them to work on DC.
The advantage of these is that they come in a insulated case.

I do not know how to copy the pictures here.