What is a unbalanced AC transformer?

Started by Uriah in sci.electronics.basics13 years ago 4 replies

I need to provide a 10VAC power supply to a cirris cable tester and they said it was unbalanced. It is a three pin input with the center being...

I need to provide a 10VAC power supply to a cirris cable tester and they said it was unbalanced. It is a three pin input with the center being neutral and each side is hot 10VAC but it is unbalanced. What do they mean by unbalanced? How would I wire that up? And is there a way to tell how to wire it in from looking at the device, I don't have the that power supply. Thanks Russ


Power Supplies

Started by Kari Laine in sci.electronics.basics13 years ago 9 replies

Hi, I am trying to find schematics for PSUs. I found one, probably good one, but it was very complicated and used an IC, which I probably...

Hi, I am trying to find schematics for PSUs. I found one, probably good one, but it was very complicated and used an IC, which I probably won't get anywhere. So any good links welcome. I understand the sub 3A PSUs somehow. But for example a 12V/60A ones are mystery to me. One person told me that they use FET's. Are they basically like the PC Power supply? But how they make the controlla...


Building a linear power supply

Started by Andrew Wagstaff in sci.electronics.basics11 years ago 8 replies

Hi I'm looking at building a linear power supply. I'm thinking of using a 12V 300VA torodial and linear regulators. I really want a power...

Hi I'm looking at building a linear power supply. I'm thinking of using a 12V 300VA torodial and linear regulators. I really want a power supply that can be used to power both AT and ATX computer motherboards, has got variable current limiting (3.3V, 5V and 12V) and displays current. I haven't seen anything in the marketplace, so I was looking at building my own. The voltage and cu...


How to power my circuit.

Started by Daniel Pitts in sci.electronics.basics10 years ago 50 replies

Hello, So far, all of my circuits have had the power supplied by an Arduino (compatible) board. I'm going to try to change the setup here a...

Hello, So far, all of my circuits have had the power supplied by an Arduino (compatible) board. I'm going to try to change the setup here a little, and design a circuit that has just an ATTiny in its place, but now I have to think about power supply. The circuit I'm envisioning is going to have three Texas Instruments "TLC5916" constant-current sink's, powering one column of a multi...


How to get 1.5 volts out of a wall-wart power supply's 3 volt output...I am new to this group I believe anyways...Nice to meet you all!

Started by Daniel in sci.electronics.basics9 years ago 19 replies

Hi, I have recently been trying to get 1.5 volts (or anything other than th= e power supply's rated 3 volts for that matter) out of a wall-wart 3...

Hi, I have recently been trying to get 1.5 volts (or anything other than th= e power supply's rated 3 volts for that matter) out of a wall-wart 3 volt p= ower supply. The wall-wart power supply is dc in output at 3 volts and even= if I connect a 300 ohm resistor in series with the wall-wart power supply = and the load (a 1.5 volt clock, old style analog clock)and when i measure t= he voltage...


DC 17V from PC power supply?

Started by Mr. Man-wai Chang in sci.electronics.basics9 years ago 22 replies

1. If I shorted the +5V and +12V in the molex connector, would I get +17V? What's the max. current? 2. Could I use 17V to charge a...

1. If I shorted the +5V and +12V in the molex connector, would I get +17V? What's the max. current? 2. Could I use 17V to charge a notebook battery rated 16V and 3.8A? Would it hurt the battery? -- @~@ Remain silent. Nothing from soldiers and magicians is real! / v \ Simplicity is Beauty! May the Force and farces be with you! /( _ )\ (Fedora 18 i686) Linux 3.9.6-200....


Benchtop Power Supply Options

Started by Jurd in sci.electronics.basics8 years ago 88 replies

Hello again, It is time for me to acquire a better bench top power solution. Most of the time I will use it to power a breadboard for...

Hello again, It is time for me to acquire a better bench top power solution. Most of the time I will use it to power a breadboard for experimentation. I used a wall wart for awhile until it got super noisy, and batteries are a hassle. I was about to go for something like this: http://tinyurl.com/qexphfy And then attach something like this: http://tinyurl.com/qc5e9ma to the leads ...


Power supply current?

Started by Peter Percival in sci.electronics.basics2 years ago 24 replies

I wish to buy a power supply delivering up to 500V for experiments with thermionic valves. What would be a suitable current?

I wish to buy a power supply delivering up to 500V for experiments with thermionic valves. What would be a suitable current?


Using a 12V 2A power supply direct and with 3V voltage divider?

Started by Anonymous in sci.electronics.basics8 years ago 50 replies

I have forgotten everything I learned in the single electrical science class I took in college 25 years ago. Please forgive my ignorance. I...

I have forgotten everything I learned in the single electrical science class I took in college 25 years ago. Please forgive my ignorance. I have a single 12V 2A power supply. I want to simultaneously power a 20W 12V fan and supply a 3V 2mA current via a voltage divider. The fan would be connected direct to the +/- of the PS while a voltage divider with R1=4500 and R2=1500 would provide the...


Cheap oscilloscope kit

Started by Peabody in sci.electronics.basics6 years ago 6 replies

I recently built the JYE Tech DSO-150 Shell oscilloscope kit (#15001K) that I got from Banggood for $24 plus a power supply. These are...

I recently built the JYE Tech DSO-150 Shell oscilloscope kit (#15001K) that I got from Banggood for $24 plus a power supply. These are single-channel, low-frequency scopes, but would be useful for things one might do with an Arduino or similar microcontroller, such as stepper motors and servos, plus of course general audio stuff. The bandwidth spec is 200 kHz, but I suspect the display...


Thermopile power supply in water heater control

Started by bob prohaska in sci.electronics.basics5 years ago 12 replies

I recently bought a gas water heater and made a point of getting one that didn't require external electrical power to operate. To my...

I recently bought a gas water heater and made a point of getting one that didn't require external electrical power to operate. To my astonishment, it nonetheless came with what behaves like a digital controller, complete with a green LED status light that must require close to 3 volts to turn on. The electronics are operated from a standard Honeywell thermopile generator producing 750 ...


Transformerless power supply

Started by amdx in sci.electronics.basics2 years ago 7 replies

Is it reasonable/possible to build an 8 amp 20 V transformerless power supply from a 120Vac line. I calculate about 180uf plus or minus...

Is it reasonable/possible to build an 8 amp 20 V transformerless power supply from a 120Vac line. I calculate about 180uf plus or minus depending on other components. Maybe 9- 20uf caps in parallel? I'd like to build it into a leaf blower. All plastic, absolutely no metal exposed. I think I've answered my question, I have 12, X rated caps in my junk box, but they are only 1uf....


Transformerless Power Supply

Started by amdx in sci.electronics.basics4 years ago 10 replies

Is it reasonable/possible to build an 8 amp 20 V transformerless power supply from a 120Vac line. I calculate about 180uf plus or minus...

Is it reasonable/possible to build an 8 amp 20 V transformerless power supply from a 120Vac line. I calculate about 180uf plus or minus depending on other components. Maybe 9- 20uf caps in parallel? I'd like to build it into a leaf blower. All plastic, absolutely no metal exposed. I think I've answered my question, I have 12, X rated caps in my junk box, but they are only...


Rope Light Circuit

Started by Bret Cahill in sci.electronics.basics2 years ago 4 replies

The sealed-up-in-plastic power supply comes with the plug, 110v U.S. or 220= v EU. On a 110 v AC U. S. plug the output appears to be 110 v DC...

The sealed-up-in-plastic power supply comes with the plug, 110v U.S. or 220= v EU. On a 110 v AC U. S. plug the output appears to be 110 v DC and 220 AC on a = volt meter. The LED part of the rope light plugs into the output of the power supply. = It looks like two rails go the length of the LED section which can be cut e= very meter at a marked location. Some LEDs can burn out while t...


Power supply trips CU

Started by RobH in sci.electronics.basics2 years ago 15 replies

I bought a 12volt 8.5amp TDK Lambda power supply from Radio Spares to replace a Mean Well 12v 8.5a supply which had failed after 3...

I bought a 12volt 8.5amp TDK Lambda power supply from Radio Spares to replace a Mean Well 12v 8.5a supply which had failed after 3 years. https://uk.rs-online.com/web/p/embedded-switch-mode-power-supplies-smps/8139099/?sra=pstk I connected it up to a 3 pin plug with a 13A fuse. When I plugged it in to an extension socket, which had a 13amp fuse, to check the output voltage, it tripped ...


Really Basic Power On Question

Started by Bret Cahill in sci.electronics.basics2 years ago 1 reply

This must be a really really common problem and the only reason it is diffi= cult to find on youtube is the wrong search terms: If a device...

This must be a really really common problem and the only reason it is diffi= cult to find on youtube is the wrong search terms: If a device has a power on button latch switch and you want it to turn on a= nd off like a light bulb, i. e., when the power supply is plugged in or a r= elay connects the power, or for solar, when the sun comes up, is it a commo= n solution to run a wire from th...


PSU for valves

Started by Peter in sci.electronics.basics2 years ago 12 replies

I thought I'd experiment with a few valve circuits (just for fun). So I'll need an H.T. power supply and I'm looking at...

I thought I'd experiment with a few valve circuits (just for fun). So I'll need an H.T. power supply and I'm looking at this: https://www.timstar.co.uk/el120300-high-tension-ht-power-supply.html It supplies up to 300V at 60mA. My question is, is 60mA sufficient? -- When, once, reference was made to a statesman almost universally recognized as one of the villains of this century, in order...


(accidentally) shorted a mosfet's drain and source

Started by Michael Darrett in sci.electronics.basics4 months ago 5 replies

For a project I noticed my Arduino PWM pump controller (basically just an Arduino, MOSFET, and protection diode) was behaving oddly, so I powered...

For a project I noticed my Arduino PWM pump controller (basically just an Arduino, MOSFET, and protection diode) was behaving oddly, so I powered the pump directly from the 12V power supply, turning it off and on as needed manually. I looked more closely at my breadboard, and noticed the drain and source were touching. The circuit had been running for a few minutes this way. Did I damage my...


Confirmation needed

Started by Bob Engelhardt in sci.electronics.basics1 year ago 5 replies

I'm going to make a 12v DC power supply with a linear reg. I will half-wave rectify 12v AC and have a smoothing cap. The load is only...

I'm going to make a 12v DC power supply with a linear reg. I will half-wave rectify 12v AC and have a smoothing cap. The load is only 10ma. So: 12v RMS is 17v peak, minus the diode drop of 0.7 is 16.3v peak. Using a 47uF cap, the ripple will be 3.5v p-p. So the min voltage into the regulator will be 16.3-3.5 = 12.8. Ripple calculated from Vpp = i/fC (.010/(60*47e-6). Am I missing ...