Why is there a need to have a flyback diode in parallel to the motor?
A flyback diode or freewheeling diode is placed with reverse polarity from the power supply and in parallel to the relay’s inductance coil. The use of a diode in a relay circuit prevents huge voltage spikes from arising when the power supply is disconnected.
Is it appropriate to put a protection flyback diode across the motor in an H bridge circuit?
H-bridge circuit flyback diode implementation Unfortunately, when using an H-bridge circuit, a single flyback diode will not suffice. Since there are multiple current pathways, there must be four diodes to provide a path for the induced voltage as shown in Figure 5.
What should the voltage be for a flyback diode?
The snubber diodes or Zener diodes must be rated at full motor current as that is what will be diverted through them when the motor is switched. If you need to clip in both directions use Zeners, set the voltage to 12.5V so they only turn on during flyback.
Can a Zener be used as a flyback diode?
The solution of Figure 3 is probably the most elegant as it uses only two components which can be placed at the motor and requires no additional wiring. The snubber diodes or Zener diodes must be rated at full motor current as that is what will be diverted through them when the motor is switched.
What happens to a fly back diode when the switch is cut off?
The motor functions normally, and the diode essentially doesn’t do anything. When the switch is cut off, however, the flyback diode’s orientation is now forward-biased with respect to the negative-reacting inductor.
Why are snubber diodes called Flyback diodes?
You may have heard the term flyback diode — also known as, “snubber diode,” “suppressor diode,” and many other names. Regardless of their name, flyback diodes can be an important tool to prolong the life of your inductive circuits. Inductor voltage spikes: switch arcing