hi, I am doing a project in which it is intended to design a backup power unit suitable for maintaining power for a small motor. If line power is loss it switches to battery powered inverter within less than 0.1 sec. The inverter output must be fully synchrionised to the line, so that there is limited inrush current when the switching takes place.the unit should wait atleast 20sec. I have got the querry that can I use A relay for controlling the time delays.
Most of UPS devices use relays, so you should be fine ..
Make sure the current rating is adequate ..
Alternatively, you can use solid state relay .. this thing is fast and can be on or off within 20ms ..
Most of UPS devices use relays, so you should be fine ..
Make sure the current rating is adequate ..
Alternatively, you can use solid state relay .. this thing is fast and can be on or off within 20ms ..
Thanks fot the time and consideration you gave in reading and answering my querry. But Sir can you help me with what sort of relays I can use for controlling the operation and how to do the Switching. I have already designed the Inverter ckt. for converting the 12V DC to 120V AC but I am Struggling On how to proceed with the Time Delays and the Switching operations.
One engineer here uses a PIC for this sort of thing. I prefer the 555 timer. Hold the reset line low until AC power is lost, then let it go high. Set the RC for your 20s delay. Use a small NPN transisitor off the output to drive your relay. Good luck.