When you choose 0-5Vdc signal, you have to use a voltage/ current transducer with 0-5Vdc output, the input range of the transducer is according to your load range, it would be better to choose a transducer with a range 1.5 times of your load. 

When you choose 0-10Vdc signal, you have to use a voltage/ current transducer with 0-10Vdc output, the input range of the transducer is according to your load range, it would be better to choose a transducer with a range 1.5 times of your load. 

When you choose 4-20mA signal, you have to use a voltage/ current transducer with 4-20mA output, the input range of the transducer is according to your load range, it would be better to choose a transducer with a range 1.5 times of your load. But when you use control boards from us - Shenzhen Sinepower Technlogy Co., Ltd, the feedback signal would still be 0-5Vdc signal even if the input signal version you choose is 4-20mA. This is for accuarcy's sake. 

Connect the transuducer output ternima to the SCR firing card (thyristor control board), and adjust the signal percentage, you will get the related voltage or current value you need.

For IF, some customer may need 0-75mV if they have to use a shunt in their system. Our control boards are using the international shunt signal 0-75mV, pls donot use shunt with other signal shuch as 0-60mV. It has to be 0-75mV, if not, the accuarcy will be incorrect, you will not get the correct current vaue you need.

A potentiometer can be used for adjust the percentage of the given signal in close loop, but for open loop, it only related with the range you set by LCD or by PLC.

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