This timed control turns the output load on and off and then repeats the cycle. Each position on the knob from LO to HI represents a specific cycle time where the on time ranges from 6 to 100 percent. For example the LO setting represents a total cycle of 60 seconds with an on time of 4 seconds. This type of control can be used to regulate the temperature of resistive loads. The pilot light on the front will glow when the load is on.

Please Note: Effective March 2026, the Digi-Sense Variable- Time Output Controller Model number 104A PL312 has now been rebranded Cole-Parmer under Model number TC1000. All the same great features and specifications, just with a new and improved look.