Pressure transducers operate in a similar fashion to pressure switches. Pressure transducers are used with computerized climate controls where pressure switches are typically used with non-computerized control systems. Pressure transducers have additional terminals within the device to allow for communication with the ECM controlling the HVAC system. The function of the transducer is essentially the same as the switch - to control compressor operation based on pressure conditions. However, the transducer can communicate very precise pressure readings, where the simple open/closed switch cannot. These precise pressure readings are used by the ECM to control compressor cycling and compressor speed for systems that use a variable speed or variable displacement capable compressor. Transducers are used in traditional 12v/24v systems and also used in High Voltage (HV) Electrified systems where HV compressors are used.