Sertel Electronics Pvt. Ltd. Supplies Central and Satellite Clocks. Sertel Electronics Pvt. Ltd. Is an ISO 9001:2000 certified company and develops GPS Based Time Synchronisation System. The Central and Satellite Clock is used to display same time in a number of locations regardless the distance. It gives time related signals for synchronising the time of microprocessor based clock system. It is synchronised with UTC or IST by monitoring by STFS Decoder or GPS Receiver. It has built in Reserve Power facility for keeping the central clocks operational.