Why is the need for NOT gate between relay & microcontroler when interfacing a relay to a 8051 microcontroler?

3 ⤊

Why is the need for NOT gate between relay & microcontroler when interfacing a relay to a 8051 microcontroler?

2006-11-11 03:14:23 · 3 answers · asked by Anonymous in Science & Mathematics ➔ Engineering

3 answers

Besides buffering the output to provide a higher drive level. Another factor is that in reset the 8051 outputs are at a high level. So your circuit needs to be designed to have the relays on or off as desired in reset or startup.

2006-11-11 03:29:46 · answer #1 · answered by rscanner 6 · 1⤊ 0⤋

To provide more drive and isolate the microcontroller from the relay.

2006-11-11 11:22:33 · answer #2 · answered by Phil O' Brien 3 · 1⤊ 0⤋

If I am not wrong it is a buffer NOT gate capable of driving enough current to energise a relay.

2006-11-11 11:22:49 · answer #3 · answered by dwarf 3 · 1⤊ 0⤋