Material :

1 electronics time switch RE-LC014 off delay (220 v).

1 relay RHN 421 M (220 v).

1 base for relay RH.

1 push button.

1 socket 2 Poles - 220 v. (that can be half fitted)

1 transformer 220 v - 5 v - 3 volts-amp.

1 bridge of diodes BC 250C.

1 polarized condenser 2200 µF - 16 volts.

1 buzzer 6 volts.

3 m of cable 2 x 1 mm².

1 plug 2 Poles - 250 v - 6 amp.

Advice :

The time switch (Telemecanique) goes from 2 to 60 mn and is fixed on a bar. (Omega)

The best place for the whole is a Teko box of 215 x 130 x 80 mm.

The relay and its base plate will be assembled lying.

The electronic things will be soldered on to a printed circuit you will have before hand engraved.

You can add a second socket without any time switch. (for example)

The control will be cabled in 0,75 mm² and the power in 1,5 mm².(input, socket and output)

The sound option is not obligatory but very useful, a little surprising for the beginning though.

Explanations :

The assembly being connected, you just need to press the push button and it supplies the time switch then the relay starts.

When the contacts 11-14 and 24-21 are closed, they put the plug under tension. When the contact 31-32 is opened, it cut the buzzer circuit.

The condenser is charging.

At the end of the time (20 mn for example), the time switch is cut and the relay is not supplied any more.

The condenser is discharging in the buzzer which starts to vibrate for a few seconds.