☑ Diode Protect Transistor

The inductor does not cause a negative voltage at the collector of the transistor when it is turned off. The counter emf voltage is opposite from the applied voltage so the diode goes into forward bias in that moment.

Signal Diode And Switching Diode Characteristics

Reverse Polarity Protection Circuit Using Diode Or P Channel

Straight Insertion Transistor 2sc1383 Large Chip To 92l Environmental Protection Transistor

The base of the transistor should never be not connected to anything.

Diode protect transistor. But the diode is there to prevent damage to the transistor from the voltage spike that can come out of the coil when power to it is shut down thats what the sketch comments say. Its drive is 2v or 0v through the 10k. A transient voltage suppression tvs diode also transil or thyrector is an electronic component used to protect electronics from voltage spikes induced on connected wires.

Usually an inductor causes hundreds of volts. Diodes thyristor surge protection devices tspd provide lightning surge suppression for intra building protection according to bellcore gr 1089 and system level protection according to iec 61000 4 5. Either way is ok the second one is usually used to express the circuit in a coil driver transistor like a tip122 transistor.

If you reverse bias the base emitter junction by taking the transistors emitter to 6rmv more positive than the base it will breakdown and begin conducting. Overvoltage protection circuit using zener diode. The diode is in place to protect the transistor from reverse vbe breakdown.

As long as the transistor will survive vcc it will not be harmed. Diodes data protection devices are a rapidly expanding portfolio targeting best in class esd performance with a wide range of selectable package options to address customer specific needs. Put a diode across the primary of your cars ignition coil and see how far you get literally.

So far so good. Because the diode conducts during counter emf. The voltage spike is positive and is only 96v that will not harm the transistor.

A parallel protection diode allows the current to go on circulating in the coil. This method is a more straightforward one wherein the circuit is designed to cut off the power to the load side when the voltage exceeds the given set values. You havent listened to what was said before you need a better transistor.

The diode will stop this happening by shorting out the inductance when its volts are above vcc. The parallel diode restricts the reverse voltage across the coil so that the total voltage seen by the switch transistor does not get too big. The primary of an ignition coil peaks around 300v it has to.

And the diode doesnt seem to enter into the basic functioning of the circuit right. When the transistor tries to turn off reducing the current a voltage spike will occur due to the inductance which would take the collector volts way above vcc positive.