Anti-seize control circuit for central heating circuit pump has timing circuit to operate pump cyclically independently of main switch

摘要

The anti-seize control circuit (1') for a central heating pump (P) has a timing circuit (11) connected in parallel with the pump power switching circuit (12). The timing circuit operates the pump independently of the main control switch using a cyclic control signal (Vs). This prevents the pump seizing due to 'gumming'.