Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

What does it mean if there is 0 L on two pins in one array of transformer?

Status
Not open for further replies.
S

smiles

Advanced Member level 4
Joined
Jul 27, 2007
Messages
110
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,296
Activity points
2,096
I see that a transformer seperate clearly two arrays of pins, one for primary, one for secondary. I want to ask that if I measure Ohm of two pins in one array, the result in meter is 0.L (isolate completely), is that transformer decayed ?
And in the circuit, when I put my two test probe into two pins of primary array, it says some value of voltage but that is DC voltage (about 250V for e.g), when AC measurement, the result is about nothing, just some few miliVolt ? I see strange but don't know why :(
 

Re: Transformer

0 means short circuit or value below resolution of meter.

Secondary windings (thick wire) have usually very low resistance.

In what circuit works that transformer ?
 

Re: Transformer

I use digital meter and when two point is completely electrical isolation than it display "0.L", I always think that.
That circuit is the power supplier for computer, it is decayed, I did testing probe on the primary coil of transformer and see that. That voltage is fed from a voltage rectifier, 220VAC to 250VDC.
 

Re: Transformer

PSU for computer is switching mode converter. Because of using much more frequency than 50 or 60 Hz it has lower transformer than normal PSU.
Transformer in SMPS has windings with low resistance, you can't measure their resistance because is too low. More adequate is inductance measurement, it should be some mH (but exact value depend on working frequency of SMPS).

https://en.wikipedia.org/wiki/Switched-mode_power_supply

I think, that in your device power transistor is dead (MOSFET)

If you powering PSU form 220 (230V) AC you should have about 310-320V on main capacitor (check it and check capacitor).

ATX PSU need starting signal from mother board to start main converter (normally only stand-by converter works).
 

    S

    smiles

    Points: 2
    Helpful Answer Positive Rating
Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top