Can anyone suggest a small, inexpensive transformer which will output about 24 volts or so?
I'm going to build an outboard power supply for my bass guitars with active electronics. Also to drive LED's which are on-board. The final output should be 18-24V 10 mA. DC. I'll be running the power along a 3 conductor mic cable with pin 1 as the power.
I would build a power supply with regulator, rectifier bridge and caps to filter and smooth the power - lest it make noise in the pickups.
I'm assuming I will suffer some voltage drop with this, so I think Something like a 110 Volt AC to ~24VDC transformer would be fine, with the resultant clean power after my filtering hopefully around 18-20 Volts DC.
I like torroidals, but I'm open to others, and want to keep this low-budget.
Suggestions?
I'm going to build an outboard power supply for my bass guitars with active electronics. Also to drive LED's which are on-board. The final output should be 18-24V 10 mA. DC. I'll be running the power along a 3 conductor mic cable with pin 1 as the power.
I would build a power supply with regulator, rectifier bridge and caps to filter and smooth the power - lest it make noise in the pickups.
I'm assuming I will suffer some voltage drop with this, so I think Something like a 110 Volt AC to ~24VDC transformer would be fine, with the resultant clean power after my filtering hopefully around 18-20 Volts DC.
I like torroidals, but I'm open to others, and want to keep this low-budget.
Suggestions?
Try All Electronics in Van Nuys.
I don't think there is much to gain with a toroid. AE can set you up for <$10. Don't forget to look at their AC wall transformers. The copper can be extracted, but I always just use them as is, insulating the 120v connections if I'm putting it all (transformer, rectifier, filter caps, etc.) into one enclosure.
Also, 10mA is underestimated. I'd look at, say, #ACTX-2412. 24VAC @ 12VA for $6.00. It'll make a stout supply with enough juice for some future add-ons.
I don't think there is much to gain with a toroid. AE can set you up for <$10. Don't forget to look at their AC wall transformers. The copper can be extracted, but I always just use them as is, insulating the 120v connections if I'm putting it all (transformer, rectifier, filter caps, etc.) into one enclosure.
Also, 10mA is underestimated. I'd look at, say, #ACTX-2412. 24VAC @ 12VA for $6.00. It'll make a stout supply with enough juice for some future add-ons.
ANTEK (or was it ANTEX?) has a wide offer in transformers of all sizes.
Or plain search Mouser , and there's always EBay.
Doubt you'll easily get something smaller than 24VAC 500mA (might find a 250mA) because those are popular sizes and so easier to find at a reasonable price.
You'll get around 30/32 Vdc Raw, easy to regulate and clean down to 24V dc .
EDIT: simulposted but as you see, we all say basically the same.
And please say toroidals, not torroidals, thanks.
A toroid is something that looks like this geometrical shape:
while torroid rhymes with hemorrhoid.
Or plain search Mouser , and there's always EBay.
Doubt you'll easily get something smaller than 24VAC 500mA (might find a 250mA) because those are popular sizes and so easier to find at a reasonable price.
You'll get around 30/32 Vdc Raw, easy to regulate and clean down to 24V dc .
EDIT: simulposted but as you see, we all say basically the same.
And please say toroidals, not torroidals, thanks.
A toroid is something that looks like this geometrical shape:
while torroid rhymes with hemorrhoid.
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As Sofaspud indicated, All Electronics provides an excellent product -
12V / 1A OR 24VCT / 500MA PC MOUNT TRANSFORMER | All Electronics Corp.
This is a splitpack transformer, which will not pass noise as easily as typical toroidal transformers, and has minimal stray fields.
12V / 1A OR 24VCT / 500MA PC MOUNT TRANSFORMER | All Electronics Corp.
This is a splitpack transformer, which will not pass noise as easily as typical toroidal transformers, and has minimal stray fields.
Keep in mind that your 24V AC will be around 33V DC after the rectifier and the first capacitor.
I've always used Antek Transformers, they are awesome. Unfortunately how they work and the VA thing is a mystery. WHICH one would you recommend?
VA is calculated by multiplying voltage with current. E.g. if you want 10VAC on the secondary with a current requirement of 3A you would look for a transformer with at least a 30VA rating. Bigger doesn't hurt.
Good thoughts, thank you! I get AE's weekly email with some screamin' deals. Unfortunately their shipping charges often kill it.
I guess I don't have to get super close to my hoped-for output, as long as it's comfortably over. Was just hoping to avoid overkill?ANTEK (or was it ANTEX?) has a wide offer in transformers of all sizes.
Or plain search Mouser , and there's always EBay.
Doubt you'll easily get something smaller than 24VAC 500mA (might find a 250mA) because those are popular sizes and so easier to find at a reasonable price.
You'll get around 30/32 Vdc Raw, easy to regulate and clean down to 24V dc
EDIT: simulposted but as you see, we all say basically the same.
And please say toroidals, not torroidals, thanks.
A toroid is something that looks like this geometrical shape:
while torroid rhymes with hemorrhoid.
And, yes, toroidals, I shall not err again! 🙂
I REALLY like this idea. After all, it doesn't HAVE to be toroidal.
I guess I'm kinda stuck with big resistors in my basses to get the voltage down to 18? Is there a power supply design which halfs the voltage? (I'm kinda new to it, always looking for the most voltage...)
Thank you all for the great replies! 🙂
I didn't know how close you were to the north side of LA. But AE does have all the other parts you'd need for your PSU. Use a voltage regulator to set the output.
Get a transformer with a lower voltage secondary. Decide if you want to use a regulator. Check the data sheet for the minimum voltage drop of that regulator at given current.
Install this PSUD2 on your computer. Drop the default secondary resistance of the transformer from 31 to 3 Ohm. Play around and you will get an idea what's happening.
Double the regulators operating voltage (drop) and add this to the output voltage you are shooting for. From there check the secondary voltage your transformer needs for that. Assuming that number 17.3V get a 18V transformer and set the regulator to the output volateg you need.
sprinkler valves work off 24VAC so they should be very plentiful and cheap to be had at garage sales , salvation army, 2nd hand type of stores. IMO wall warts in general are very easy to work with, regarding safety.
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Good point. A SMPS would work as well and be cheaper, smaller and lighter than a transformer based regulated supply.
Huh... I was always led to believe there's more to it than that. Is it really that simple?
Never cut a wall wart open. I'm assuming it's just a small transformer in a plastic box, right? It would be an easy way to go...
It will be a switch mode power supply (SMPS) in a plastic box. Check the website of Meanwell and pick your unit.
Harbor Freight sells a battery maintainer Vout = 13.8 VDC
it uses a wall wart 16VAC ~ 500mA and a small regulator IC mounted separately in a small plastic housing. you could use that or replace the transformer unit with another and mod the PCB. since your current is low ~ 10mA anything else is overkill.
it uses a wall wart 16VAC ~ 500mA and a small regulator IC mounted separately in a small plastic housing. you could use that or replace the transformer unit with another and mod the PCB. since your current is low ~ 10mA anything else is overkill.
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All right, so if we use the transformer pmcapp suggests, 12V / 1A OR 24VCT / 500MA ,
I placed it in PSUDII. With the aim of very quiet power, (DC 9V batteries are very quiet) is this a good start?
View attachment PSU_Design_01.zip
I placed it in PSUDII. With the aim of very quiet power, (DC 9V batteries are very quiet) is this a good start?
View attachment PSU_Design_01.zip
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