# Transformer -- power supply

Discussion in 'The Projects Forum' started by simon74, Apr 9, 2010.

1. ### simon74 Thread Starter New Member

Apr 8, 2010
15
0
hi well i have just made a transformer power supply.
i took the steps in the instructions.

now i took a small transformer i am getting reading of

.77w ,on 1 side
.87w ,the other side
.163 across the board

am i right in working out this is a 16w transformer and can i test all power transformers in this way .as in the lesson iam looking for 12w ,6w per side.

thanks simon

2. ### SgtWookie Expert

Jul 17, 2007
22,202
1,793
I'm wondering what you're talking about?

How did you measure wattage output?

P=E^2*R
P=I^2*R
P=E*I

Fill in the missing parts of the equations.

3. ### simon74 Thread Starter New Member

Apr 8, 2010
15
0
i measured using an ohms meter as in the instructions.
i took a reading from center wire ,and right wire
center wire ,and left wire
then a reading of left and right wire equaling the equation,or so i believe.
sorry i could be way of the mark.
and sorry i dont understand the terms you have asked me,possibly dumb in ,mathamatical terms

4. ### Bychon Member

Mar 12, 2010
469
41
Ohms are not watts. You look like you don't have a clue right now. Another way to say that is: your data is irrelavent, your questions can't be answered with this information, and your conclusions are all wrong. Somebody will be along in a little while and put in a link to stuff you need to read.

Sorry if I sound harsh. It's a personality problem. I have a deep seated belief that facts shouldn't cause emotional distress. Please don't get all distressed.

Apr 5, 2008
18,882
3,712
Hello,

On some computers the Ω-sign is converted to w due to a font issue.
You can use the Ω-sign from the Symbols box (below the smilies) on the right.

Bertus

6. ### Wendy Moderator

Mar 24, 2008
21,438
2,958
What instructions?

Ohms doesn't tell you anything meaningful, though it can tell you if a transformer is shorted. There are exceptions, but typically there should be no continuity between the windings.

The AAC book does cover transformers.

Are there any markings on these units? If not you will have to test them, but do some reading first. Since you will likely be dealing with line voltages and currents please don't skimp on the reading, it can be dangerous.

7. ### simon74 Thread Starter New Member

Apr 8, 2010
15
0
no ,i know ohms aint watts.
and no iam not distressed lol ,i prefer simple awnswers.to simple question.
other than following the procedure possibly in the wrong manor settings
with my multi metre .and yes i prefer plain english ,abrupt as you may want to be.no piont me filling my head with math when i know iam not a mathamatical type of guy lol . dont make me dumb,the dumb ones are people that dont understand ,thinking knowing it all and well they dont know everything .thankyou .

8. ### Wendy Moderator

Mar 24, 2008
21,438
2,958
Problem is, you are so far off base that we know you are new. What you want to do can't be done with a multimeter by itself.

This is a no flame zone, we treat you civilly, and get treated the same.

Ask questions that don't have basic wrong assumptions, and you'll get a lot more in return.

If you don't know where the wrong assumptions are, ask. We will help.

9. ### simon74 Thread Starter New Member

Apr 8, 2010
15
0
i wearnt assuming i was asking if id done somthing correctly.
obviously not ,and yes i do now realise i need a voltmeter,aswell as the multimetre.
also i know iam new,hence the reason for joining such a site.
id think to learn as iam trying to do.

10. ### Wendy Moderator

Mar 24, 2008
21,438
2,958
Problem with transformers is you don't know what gauge of wire they are using internally. Resistance counts, but the number of windings count more (as is explained in the link I gave). If the transformer is properly labeled all the information you need is on the package, otherwise you have to power it up and try it out.

There are other parameters that make a large difference, such as the iron core. With the quantity of Chinese junk flooding the market you don't really know what you have, though quality will tell.

Having the specs on the case of the transformer, or having a part number that can be referenced to is the best hope.

11. ### simon74 Thread Starter New Member

Apr 8, 2010
15
0
yes i understand ,and well may have over looked things.
i came looking at the tube op amp,and me being a want to do person.
have jumped across alot of initial things i need to learn.
i know i need to take a step back and re step my way into getting correctly
setup and various other areas i have over looked,need looking at first.

i have read in the work sheets ,that .

A multimeter is an electrical instrument capable of measuring voltage, current, and resistance. Digital multimeters have numerical displays, like digital clocks, for indicating the quantity of voltage, current, or resistance. Analog multimeters indicate these quantities by means of a moving pointer over a printed scale.

and iam not trying to justify iam right or wrong,as with learning anything
i know iam probably wrong more times than iam right.but anyway thanks
for the help .i will stick with playing and building guitars lol thanks

12. ### retched AAC Fanatic!

Dec 5, 2009
5,201
316
There is a bunch of information to be had here. At the top of every page is the E-Book. That has what you need to get a grasp on electronics. And this forum.

What was the original problem? Were you not getting what you expected from your transformer?

13. ### simon74 Thread Starter New Member

Apr 8, 2010
15
0
yes i understand their is lots of imformation .
iam trying to take on as much as i can.
but rather than starting ,from the begining,and working through.
i came accross tubes and had visions of jumping in and making somthing from them.i do understand this in itself is not easy and i need to grasp more basics prior to jumping in feet first.Also i was quite happy with what i acheived yesterday ,more not a problem ,more wondering if i had done somthing correctly.
and thanks again

14. ### atferrari AAC Fanatic!

Jan 6, 2004
3,071
1,148

I do not believe a single word of all this.

Apr 5, 2008
18,882
3,712
Hello,

For basic info on transformers take a look ik the links of this EDUCYPEDIA page:
http://www.educypedia.be/electronics/electricitytransformers.htm

There are pages like that for other components:

Passive semiconductors technology: Batteries Diodes Photovoltaic systems Switches Buzzers Diode types Quartz crystals Thermoelectric Capacitors General overview Relays Transformers Capacitor types Heat Sinks Resistors Transformers-RF Coils Photo diode Resistors-Nonlinear Transformer types

Bertus