Make Electronics-Exp 8b

THE BUZZING OSCILLATING RELAY: In this configuration you are meant to play with the switch to the right of the relay. In the experiment it is a push-button but I thought it is easier to simulate and measure with a simple switch. As the switch is originally open, the current flows through the Red LED, through the Relay in its relaxed state and back to the negative side (conventional current). As we close the switch to the right of the relay, the current now goes through the relay (coil section of the relay) and switches to its non-relaxed state. This opens the path for the current through the blue LED and back to the negative side of the DC source. At the same time though, the current that energized the coil in the relay and allowed to switch it to its non-relaxed state (Blue LED on) has now no return path back to the power source. The reason is that the only return path for the current that energizes the coil in the relay would be through the path taken via the red LED through the relay's switch (relaxed state). As a result the relay goes back into it relaxed state right away (red LED on). This in turns re-starts the cycle as the current can once again re-energize the coil that allows the relay to change state and lights the blue LED. This back and forth in the relay happens so quickly that the red LED seems to be constantly on and the blue LED seems to be always off. The relay is also triggered back and forth so quickly that it starts making a BUZZING sound. In a real experiment you would not want to keep that relay buzzing for too long as it would end-up burning out (or one of the nearby components). To visualize the back and forth in the relay's switches, I put the simulation speed at around 250ms/s.

published 7 years ago