Hello all, in new here so please excuse any issues and or ignorance I may have. What I am trying to do is convert a 24v PWM signal to either a variable 12vdc or 24vdc. The premise behind this is I have a 24v PSU that drives a main board and cannot be swapped out as the board controls multiple devices that still require 24v. The board currently supplies 2 fans and a heater capsule with 24v through a shared wire to the breakout board where it's separated into the 3 devices. Each device has it's own 0v line back to the board which controls them individually with a PWM signal through the 0v line. What I am trying to do is replace the fans with a 12v and 24v fan. The 12v fan is 4 wire PWM but I only have the 2 wires from the board. The 24v fan is DAC/analog (I think I have that right), and as such doesn't play nice with the pwm signal. Is there any possible way to do this? preferable as close to the main board as possible, but at the breakout board would be possible as well. I realize the two fans would have to be on separate circuits as the have different voltage and their own pwm signaling but if like to see if this can work. Thank you for any input that any of you may have and if I've left any information out please ask and I will do my best to provide the information needed. I do have an understanding of circuits and schematics to a certain degree but circuit and component assembly is new to me.
24v PWM to 12 or 24vdc
- Thread starter Naemion
- Start date
A Schematic is required.
Do You have a dead-24-Volt-Fan that You want to replace with
a 12-Volt-Fan that You happen to have on hand ?
Why are You changing one of the 24-Volt Fans to a 12-Volt-Fan ?
What is a "0-Volt-Line" ?,
Ground ?,
Common ?,
Switched-Ground-PWM-Signal-Wire with a Pull-Up-Resistor ?,
Other ?
.
.
.
Do You have a dead-24-Volt-Fan that You want to replace with
a 12-Volt-Fan that You happen to have on hand ?
Why are You changing one of the 24-Volt Fans to a 12-Volt-Fan ?
What is a "0-Volt-Line" ?,
Ground ?,
Common ?,
Switched-Ground-PWM-Signal-Wire with a Pull-Up-Resistor ?,
Other ?
.
.
.
By 0v I meant the negative wire going back to the mainboard. I am wanting to change out the fan as the 24v fan is very noisy, and the 12v is a better performing and almost silent. I can draw out the circuit by hand, but it is basically just a ribbon cable with a single 24vDC wire that goes up to a breakout board that divides up the 24v to the heater cartridge and two separate fans. The heater, and both fans have their own negative line going back to the main board, so 3 separate negative wires, and those are the wires that the mainboard uses to control the PWM. There are no ground wires or common wires, only ones that are required for each device, mainly 2 wire each.
The 12v fan would have a max of .05A. I can set the frequency of the pwm to pretty much whatever I want through software. The 24v blower fan would be a max draw of .7-.81A
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That looks like it would work perfectly! So simple also. From the looks of it though, you have the M- going to ground. Unfortunately where the fan is located I do not have have access to ground.
You'll have to run a wire back to a 0v point (relative to the +24v) - you need that for the other components as well.It can't be done with a 4-wire fan otherwise.
For the 'analog' fan I need to know the control voltage range, or the model number.
