Micro Systems & Controls manufactures Keyboard Programmable Bag Filter Timer. Micro Systems & Controls is an ISO 9001:2000 certified company. The Keyboard Programmable Bag Filter Timer of model number BF-200 is a specially developed electronic unit for controlling cleaning cycles of bag filters available in various models to suit different output requirements. The timer energizes a solenoid valve, thus triggering the momentary pulse of high pressure compressed air down into a row of filter bags. This pulse of air will expel the dust from the surface of the filter. The timer closes the valve after a specified time and the filter starts working in the ventilation mode. Two modes of operation are available namely continuous cycle and On-demand filter cleaning. In the continuous cycle operation the bags are continuously cleaned. The on-demand operation is based on differential pressure where as the filter bags become dirty, the differential pressure across the surface increases.