Driving Transformer Help

Athosworld

Member
I made a small transformer with 30 turns on primary and around 250 turns on the secondary and I want to know how to drive it. I thought I could drive it with a 2N2222 oscillator like this one

Could I just replace the LED with the primary of my transformer? What effect would this have on the circuit?
Here is my transformer
 
Sort by date Sort by votes
You will get some leakage inductance so you will probably need some supresion to stop the inductance destroying the transistor.
 
Upvote 0 Downvote
Driving a transformer with a DC average component is not desirable, since it tends to saturate the core.
Better to drive it with a push-pull output buffer stage through a large capacitor to block the DC.
 
Upvote 0 Downvote
Why is the base open?
Why is the emitter of an NPN transistor connected to the positive supply?

In other words, why are you attempting to drive a transformer with the EC reverse breakdown current?

Lastly, what are the transformer’s electrical characteristics?
 
Upvote 0 Downvote
schmitt trigger said:
Why is the base open?
Why is the emitter of an NPN transistor connected to the positive supply?

In other words, why are you attempting to drive a transformer with the EC reverse breakdown current?
Click to expand...

It's a very crude type of relaxation oscillator, that has be posted online numerous times.

When the reverse base-emitter breakdown occurs, the transistor can "trigger" like a UJT, with the forward biased base-collector junction acting in place of the normal base-emitter junction.
 
Upvote 0 Downvote
I was playing with a similar circuit recently. I had a nice polycarbonate sheet as a shield to protect my face from the possible spatter of copper wire used as an electrode - unfortunately, I spattered the window on my fluke meter.
 
Upvote 0 Downvote
crutschow said:
Well, not exactly.
I don't think it's designed to saturate, just go to near saturation.
Anything beyond saturation would not add to the output.
Click to expand...
I think an old-school car ignition has to saturate at low rpm or it won't be close to saturation at high RPM where it needs the strongest spark.
 
Upvote 0 Downvote
ZipZapOuch said:
I think an old-school car ignition has to saturate at low rpm or it won't be close to saturation at high RPM where it needs the strongest spark.
Click to expand...
I don't think that the ignition coil saturates on a car. The current is limited by the resistance of the coil, but that doesn't mean that the magnetic field is saturated.

Modern cars limit the time that the coil is turned on for, and with the coil inductance that stops the current getting too large.
 
Upvote 0 Downvote
the transformer has a ferrite core
30 turns on primary 250 on secondary (new version has 20 turns on pri and 400 on sec
The primary is 1 mm wire and the sec is 0.1 mm
 
Upvote 0 Downvote
You must log in or register to reply here.

Similar threads

  • Question
Relaxation Oscillator Help
Replies
13
Views
2K
Athosworld
A
  • Question
1980's electronic typewriter transformer bad?
2
Replies
29
Views
1K
ZipZapOuch
Test an AC Current Sensor Transformer
Replies
4
Views
550
ThomsCircuit
P
Finding unknown voltage of a transformer
Replies
13
Views
2K
paddy ryan
P
AC/DC Transformer with 240V output
2 3 4
Replies
63
Views
7K
ThomsCircuit
Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…