Ok, I added the Buzzer:
Once connected to 240v, the Blue LED will light, and the buzzer will sound for about 3 seconds then it will silence. If you wish to change the time the buzzer stays on, simply change the value of C4. The value in microfarads roughly equals the time in seconds the buzzer will sound. All the capacitors in the timer circuit should be rated for 25v. Zener Diode ZD1 is 12v @ 1w, and BUZ1 needs to be a low-power 12v Piezo buzzer. The one I used is a Projects Unlimited PI-256K.
There is also a toggle switch (S1) that lets you select between 120v and 240v output. If you don't want it, simply jumper connections 1 and 2 together and don't use 3. If you do add the switch, it must be rated for your load, I recommend at least 25A.
For safety, It's very important to use a 10ohm 1watt flameproof or fusible resistor for R1 and that C1 be .22uF and a minimum of 300 volts. (you can go higher on capacitor voltage, but never lower!)
I do not recommend anyone attempt fabrication of this project unless they are qualified to work on electronics and high voltages. All
parts in the circuit are connected to potentially lethal line voltages!
Phil, in place of S1 could you use the remaining contact on the upper relay so the neutral is used for 120 if 1 side is disconnected?
The cars I drive on a regular basis.
2011 Leaf SL, bought as 4 bar looser!
2013 Tesla S85
2015 Fusion Energi, Gas guzzler!
2016 Fiat 500e, Lease is almost over
2016 Spark EV, Lease is almost over