What is a unbalanced AC transformer?

Started by Uriah in sci.electronics.basics10 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.basics10 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.basics8 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...


Wires...?

Started by fungus in sci.electronics.basics8 years ago 16 replies

Spurred on by my first LED light setup, I'm now doing the hallway... The setup is this: There's a 12V switching power supply connected to...

Spurred on by my first LED light setup, I'm now doing the hallway... The setup is this: There's a 12V switching power supply connected to a small current regulator board ("CRB"). The CRB fixes the output current to 850mA. After that come the LEDs. I did the initial test on the table. The LED current was 850mA as it should be, output from the CRB was 10.5 Volts. I left it running for a da...


How it works ?

Started by mowhoong in sci.electronics.basics8 years ago 19 replies

A credit card size of '' Eco harmonics electricity saver card '' when place on the incoming power supply box will save 20 % on electrical bill....

A credit card size of '' Eco harmonics electricity saver card '' when place on the incoming power supply box will save 20 % on electrical bill. Can any person explain to me how it work ? Thanks and Happy New Year to the electronic group members .


Filtering a PWM signal

Started by Bob Engelhardt in sci.electronics.basics8 years ago 4 replies

I've been watching some of Dave Jones videos (EEVblog). In #225 he discusses using a PWM signal to control the voltage of a power supply. It...

I've been watching some of Dave Jones videos (EEVblog). In #225 he discusses using a PWM signal to control the voltage of a power supply. It needs to be DC to do this, so he uses a filter. He uses a first-order RC filter, with the output going to the "+" input of an op amp. With a 10% duty cycle on the input he shows the output at 10% of the input peak, with some ripple. What I don'...


reverse breakdown voltage

Started by Bernhard Kuemel in sci.electronics.basics8 years ago 20 replies

Hi seb! I tried to measure the Vrbd of LEDs and found the resistance dropping: Vr ...

Hi seb! I tried to measure the Vrbd of LEDs and found the resistance dropping: Vr R(MOhm) 3.18 244.6153846154 3.97 59.2537313433 4.23 48.6206896552 4.82 36.7938931298 5.65 27.5609756098 6.08 22.7715355805 7.61 16.295503212 I guess I have not reached the breakdown voltage and I need a power supply with more voltage. However, I wonder, what the definition of breakdown volt...


connecting wires to pencils underwater

Started by Adam Funk in sci.electronics.basics8 years ago 16 replies

I'm interested in the prospect of using pencils as electrodes for electrolysis of water, but I'm trying to figure out a way to attach the wires...

I'm interested in the prospect of using pencils as electrodes for electrolysis of water, but I'm trying to figure out a way to attach the wires from the power supply to the other end of each pencil so that the electrical connection is sound but I can seal it up to immerse (so that the exposed electrodes are underwater in tubes). Here's a pencil example, but the gases from both working end...


buying a UPS for my new PC

Started by don in sci.electronics.basics8 years ago 3 replies

i am buying a new PC that is coming with a 600 watt power supply and I have an existing APC BACKUP that has 750VA and 450 Watts....... is this...

i am buying a new PC that is coming with a 600 watt power supply and I have an existing APC BACKUP that has 750VA and 450 Watts....... is this good enough for my new PC?


Controlling a Stepper Motor.

Started by calcasmy in sci.electronics.basics8 years ago 4 replies

Greetings, To start with, I am not even a beginner and am planning to learn... I am trying to control a stepper motor. This is where I got so...

Greetings, To start with, I am not even a beginner and am planning to learn... I am trying to control a stepper motor. This is where I got so far: 1. Stepper Motor connected to power supply (12V) with darlington pair. 2. Converted USB serial signals to parallel signals for connecting to the darlington pair. 3. I wanted to use a microcontroller, but didn't want to complicate it (next ...


How to power my circuit.

Started by Daniel Pitts in sci.electronics.basics7 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...


Replacement wall-wart help needed

Started by Anonymous in sci.electronics.basics7 years ago 14 replies

This is a total "noob" question and I have done some searches but want to b= e sure before I go and purchase a replacement. I own something...

This is a total "noob" question and I have done some searches but want to b= e sure before I go and purchase a replacement. I own something called a Bitscope which I use for tinkering with electronic= s. It an older one and I'm pretty sure the wall-wart power supply is dead.= The creator of the Bitscope isn't responding to my emails so I'm sorta st= uck trying to find a replacement one a...


AC Cap Dropper DC Power Supply

Started by Jim Thompson in sci.electronics.basics7 years ago 101 replies

AC Cap Dropper DC Power Supply Anyone know of a clever way to regulate other than the typical brute-force zener clamp? ...

AC Cap Dropper DC Power Supply Anyone know of a clever way to regulate other than the typical brute-force zener clamp? ...Jim Thompson -- | James E.Thompson, CTO | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Pho...


24-30v dc power supply schematic

Started by chas in sci.electronics.basics7 years ago 28 replies

I need a schematic for a non regulated 24 or 20v dc power supply. I will be running high amps (15?) for a homebuilt induction furnace. . . . in...

I need a schematic for a non regulated 24 or 20v dc power supply. I will be running high amps (15?) for a homebuilt induction furnace. . . . in advance to one and all. . .thanks. .. chas.


Laptop power supply 20V

Started by David Harmon in sci.electronics.basics7 years ago 3 replies

The new Lenovo laptop I bought comes with an AC to 20V DC external power converter. Why such a high DC voltage? I would expect that most of...

The new Lenovo laptop I bought comes with an AC to 20V DC external power converter. Why such a high DC voltage? I would expect that most of the circuitry in there operates on 5V or even 3.3V. While they may still need 12V to power disk drive motors or something, is there anything at all that operates on anything close to 20V?


Decoupling capacitor choice for 4017 decade counter

Started by Anonymous in sci.electronics.basics7 years ago 14 replies

Hi all, I've been having some problems with a chain of divide-by-ten counters firin= g off prematurely and messing up the division. I'm...

Hi all, I've been having some problems with a chain of divide-by-ten counters firin= g off prematurely and messing up the division. I'm guessing this is a decou= pling issue (after all, what else could it be, since I'm using a hi-quality= filtered power supply that should be well up to the job). I seem to recall from somewhere that these chips need larger than usual cap= s for this purpos...


Have 5v regulator need 9 volts

Started by amdx in sci.electronics.basics7 years ago 29 replies

Hi all, Tomorrow I'm working on a power supply to replace a 9v battery. All I have is a *5 volt regulator. I think can use a voltage divider...

Hi all, Tomorrow I'm working on a power supply to replace a 9v battery. All I have is a *5 volt regulator. I think can use a voltage divider on the output, then tie the normally grounded leg to the center of my divider to bring it up to 4 volts. So I have 4 + 5 = 9 volts. If I used 5.1K and 4.3k in series to ground. that would give me 9.1 volts. However there is some current from the ...


Help explain strange behavior of my circuit?

Started by Daniel Pitts in sci.electronics.basics7 years ago 8 replies

Hello. So, I noticed something strange with my circuit, and while I can "work-around" it, I'd like to understand what's going on. I took...

Hello. So, I noticed something strange with my circuit, and while I can "work-around" it, I'd like to understand what's going on. I took my LED display project to school so I could use their DC power supply. I found that my project works (MCU runs, the LEDs light up as expected, etc...) if I connect it to an already on 3.5v to 4.0v. If I ramp up the voltage, it seems to get stuck, ...


Radio hiss. Power Supply?

Started by W. eWatson in sci.electronics.basics7 years ago 2 replies

I have a Sonido radio by Sangean. To listen to distant radio stations, I use my PC in the den, and pick up the signal from our bedroom. The...

I have a Sonido radio by Sangean. To listen to distant radio stations, I use my PC in the den, and pick up the signal from our bedroom. The signal is sent from the PC via a CCrane xmiter. Sometimes the signal is so noisy I have to put the radio on the floor flat on its back to get something decent. Last night I had this problem, but decided to take out the wall wart. Instantly, the noise...


comments on this DC power supply?

Started by Adam Funk in sci.electronics.basics7 years ago 1 reply

I came across this item, which looks like a pretty good deal to...

I came across this item, which looks like a pretty good deal to me. http://www.mindsetsonline.co.uk/product_info.php?products_id=1009985 Comments, reviews, suggestions? -- XML is like violence: if it doesn't solve the problem, use more.