Probe current voltage pin 420*4450 head diameter 5.0 over current current and voltage pin

GW MB10F 0.8A 1000V rectifier bridge

Photocoupler

There are several protection measures for thyristor overcurrent:
1. Fast fuses Common fuses have a long blow time and are used to protect the thyristors. It is very likely that the fuses have not been blown after the thyristors have burned out, so that protection is not possible. Therefore, a quick fuse dedicated to protecting the thyristor must be used. The fast fuse uses a silver fuse. Under the same overcurrent multiple, it can be blown before the thyristor is damaged. This is the main measure for thyristor overcurrent protection.
There are three ways to access the fast fuse, as shown in Figure 1. One is that the fast fuse is connected to the output (load) end. This connection protects the overload or short circuit of the output circuit, but does not protect the overcurrent caused by the fault of the component itself. The second is that the fast-blow fuse is connected in series with the component to protect the fault of the component itself. The above two methods generally need to be used at the same time. The third connection is that the fast-blow fuse is connected to the input terminal, so that the short-circuit of the output terminal and the short-circuit of the component can be simultaneously protected, but after the fuse is blown, it is impossible to immediately determine what is faulty.
The current rating of the fuse should be as close as possible to the effective value of the actual operating current, rather than the current rating (average) of the component being protected.

Figure 1 Fast fuse access method
2. The overcurrent relay is equipped with a DC overcurrent relay at the output (DC side), or a sensitive overcurrent breaker is connected to the input (AC side) via the current transformer, which can be operated in the event of an overcurrent fault, so that the input terminal The switch trips. This protection measure is effective for overloading, but in the event of a short-circuit fault, it takes a certain amount of time due to the action of the overcurrent appliance and the trip of the automatic switch. If the short-circuit current is relatively large, this protection method is not very effective.
3. The overcurrent cut-off protection uses the signal of the overcurrent to shift the trigger pulse of the thyristor to reduce the conduction angle of the thyristor or stop the trigger.