Resistance value help needed to convert 12v circuit into 5v

Thread Starter

prerakk

Joined May 21, 2015
12
Hi friends ,

i need your help in converting this gadget ( car humudifier) circuit from 12v input to 5v input. so that it can work from usb input (eg. powerbank ).
i am sure it is possible as i have seen it somewhere.

please find the circuit image in the attachement below and help me with what changes i have to do on the same board to achieve it .



thank you so much in advance for your help.
 

Attachments

ian field

Joined Oct 27, 2012
6,540
Hi friends ,

i need your help in converting this gadget ( car humudifier) circuit from 12v input to 5v input. so that it can work from usb input (eg. powerbank ).
i am sure it is possible as i have seen it somewhere.

please find the circuit image in the attachement below and help me with what changes i have to do on the same board to achieve it .



thank you so much in advance for your help.
The inductor on that board could already be part of a switch mode PSU. Identify the nearby chip for more clues.
 

wayneh

Joined Sep 9, 2010
16,114
One quick approach would be to just get yourself a 5V-12V DC-DC boost converter to get 12V out of a 5V supply. You can find these converters very cheaply on eBay. Just be sure to give yourself plenty of capacity. I mean, if the humidifier needs 1A, get a converter rated to 2A output or more, if you can.
 

Thread Starter

prerakk

Joined May 21, 2015
12
The inductor on that board could already be part of a switch mode PSU. Identify the nearby chip for more clues.
i am sorry please explain me , which component(s) to replace as i am complete noob. all i know is basic soldering

One quick approach would be to just get yourself a 5V-12V DC-DC boost converter to get 12V out of a 5V supply. You can find these converters very cheaply on eBay. Just be sure to give yourself plenty of capacity. I mean, if the humidifier needs 1A, get a converter rated to 2A output or more, if you can.
sorry bro , but i just want to modify the same as i have to do it in bulk quantity.
 

Alec_t

Joined Sep 17, 2013
10,424
I doubt there is a simple modification, such as replacing a component. A 5V input would need more than twice the current to get the same power output from the circuit. Do you have a schematic of the humidifier?
 

Thread Starter

prerakk

Joined May 21, 2015
12
please help me with the solution .
i have already posted the circuit picture. if you guys want more clear picture than i will do it too .
thanks again
 

BobTPH

Joined Jun 5, 2013
2,047
please help me with the solution .
i have already posted the circuit picture. if you guys want more clear picture than i will do it too .
thanks again
You have already been given the solution. You cannot get 12V from a 5V source without a DC to DC converter of some kind.

Bob
 

ian field

Joined Oct 27, 2012
6,540
You have already been given the solution. You cannot get 12V from a 5V source without a DC to DC converter of some kind.

Bob
The board may already have a switcher on board - but my suggestion to the TS to investigate that possibility fell on deaf ears.
 

BobTPH

Joined Jun 5, 2013
2,047
If the board is for an ultrasonic humidifier, the inductors are part of a high frequency oscillator need to drive a piezo element, so I am skeptical of your conjecture.

Bob
 

ian field

Joined Oct 27, 2012
6,540
If the board is for an ultrasonic humidifier, the inductors are part of a high frequency oscillator need to drive a piezo element, so I am skeptical of your conjecture.

Bob
Possibly - but the TS couldn't be bothered finding out what it actually was.
 

Thread Starter

prerakk

Joined May 21, 2015
12
The inductor on that board could already be part of a switch mode PSU. Identify the nearby chip for more clues.
The board may already have a switcher on board - but my suggestion to the TS to investigate that possibility fell on deaf ears.

i am sorry but i dint get what you want me to identify. as i am a complete noob and dont know anything more than replacing on board components by soldering.
 
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