Captive tripper timers, also known as captive or captive-wheel timers, are a type of mechanical timer commonly used for scheduling and controlling the operation of electrical devices or systems. They are widely employed in applications such as lighting control, HVAC (Heating, Ventilation, and Air Conditioning) systems, irrigation systems, and other timed operations.

Captive tripper timers offer the ability to set specific on/off schedules or timing intervals using rotating discs or "trippers" that engage and disengage electrical contacts. Captive tripper timers are valued for their simplicity, durability, and ease of use. They offer a cost-effective solution for automating timed operations without relying on electronic or digital technologies.

Captive tripper timers are typically used to control activities that must be performed at regular intervals.

Borg General offers heavy duty 40-amp synchronous time switches that provide accurate timing for daily or weekend programs via captive trippers.

These captive tripper timers are simple and fast to program, are synchronous motor driven, and have indicators that show the status of the timer.

Popular applications include heaters, filters, pumps, indoor and outdoor lighting, signs, fans, blowers, air conditioning, feeders, security/alarm systems, and process control.