Hey all! I am looking to make a 0.1A 12-24 DC/DC Converter. Before you say anything, I have searched the net and the forums and saw several (complicated) examples of such a converter, but all of them are rated for over 1A. I, however, am looking to build a converter that can supply only around 100mA, not more. Is there a simple diagram to build such a converter, taking into account a low power requirement?
1 amp is pretty small. Whats it for?because if its inside your computer and only drawing .1A then you can take it out of the 12volt+ and 12 volt- as ground. Mine is rated at .8A its like a 450W psu. You are looking for a buck boost type and a 1 amp is fine to use.
I am aware of the possibility of using the +12V and -12V rails on the power supply to get 24V, but would rather avoid taking out the power supply, so many molexes going everywhere =)
I am almost certain somebody here knows the solution to my question. I've seen these converters on ebay, and they have very few parts. Now, if somebody could be kind enough to give me a diagram, maybe I can try to build one myself.
You don't have to take out the power supply to follow Hydro's idea. Get a pin-out diagram (google) for the power supply to motherboard connector then splice in near it.
It's quite possible that he needs 24V referenced to the main ground in the PSU - so using the -12V rail won't work.
Your best bet, if you want this supply to be independent of the PC power supply, would be to use a couple of 12V-12V isolated DC-DC converters such as the Newport NMV1212SA, or the newer NME1212D. Because these units are 3KV isolated, you can then tie the negative output of one of the converters to the positive output of the second which will give you your isolated +24V supply. All you will need in the way of additional componentry are a couple of capacitors for smoothing. Note however that this particular device is only rated to 84mA, and the load regulation is 10%, however if you can handle this, then at least you have one solution to think about. If however, you aren't strapped for cash, you could do the same with two REC5-241-2SRWZ's for a much more stable and beefy circuit.
I just tested using the -12V and +12V rails from the power supply, and it is not acceptable for my application - I need 0V as a ground. Any last suggestions before I buy a AC-DC adapter from allelectronics?
what exactly is the application just so we know what we are working with here?, perhaps if we know what you are trying to do we could better assist.
In that case, if you just connect the -12V of the circuit I suggested above to the 0V line of your PC PSU, then you will have what it "sounds" like you need. Unless there is another reason why it would be unsuitable? As warrior Rocker says, you're not giving us a lot to go on. Edit: You could also try and get hold of a Traco TEN101215. It's unisolated, but as you seem to be tying the 0V's that shouldn't be a problem. It will also give you your regulated 24V from a 9-18V supply. It's expensive at about £35.00, but it would be a "one stop shop" for what you are after.
I have a flow meter that operates at 24V DC. I contacted the manufacturer, and it can't be converted to 12V DC operation. The flow meter outputs a voltage signal that is proportinal to the flow. Unfortunately, the ground is common to the flow meter power supply and the signal output. When I used -12V and +12V rails from the power supply, the ground for the output signal was also -12V, and I need it to be at 0. The meter only needs 30mA, so I was confident there is a simple converter that can take 12V DC rail from the power supply and convert it to 24V DC at a very low current.
I suggest utilizing one of these. They can be bought from Mouser Electronics for as little as 81 cents a piece. Other components include: Two capacitors for smoothing transients Low capacitance high frequency capacitor to set the switching frequency An inductor of about 180 uH A fast-switching diode A few resistors
