Hi,
I have added the picture of ATX PSU EE-19 Chopper Transformer for +5VSB Section . In the picture Black Dot stands for What ?? Is it related with transformer windings or other things ?? What is the meaning of these Black Dots ?? If anyone explain it, it will be very helpful for me .
The purpose of the dots is to indicate the direction of each winding relative to the other windings in the transformer. Voltages on the dot end of each winding are in phase, while current flowing into the dot end of a primary coil will result in current flowing out of the dot end of a secondary coil.
Hi,
It represents the the polarity assume at an instant the dot marked pin is +ve compared to the other pin in the same winding then all other dot marked pins will be +ve in their respective windings.
regards ani
One more thing - Can I measure the voltage between these two Pin (Dot and Without Dot Pins) ? I mean - Meter's Black Probe to "Without Dot" Pin and Red Probe to "Dot pin" . Can I measure the voltage in this way ?? If not, then how can I measure voltage of these two pins ??
One more thing - Can I measure the voltage between these two Pin (Dot and Without Dot Pins) ? I mean - Meter's Black Probe to "Without Dot" Pin and Red Probe to "Dot pin" . Can I measure the voltage in this way ?? If not, then how can I measure voltage of these two pins ??
You can measure mentioned by oscilloscope.
However I think you cannot measure voltage by multimeter because of transformer frequency at (ATX SMPS) is approximately 40-120khz and this need to special multimeter or oscilloscope to detect it.
But Can I ask - Why is it AC ?? Transformer's Pin1 is connected directly with Capacitor +Ve which is 320V and Pin3 is connected directly with Transistor 2SC5027 Collector and Pin5 is directly connected with Capacitor -Ve . Is Transistor 2SC5027 creating AC here ?