…The baby was cranky for a long time and finally fell asleep. A few minutes later the doorbell rings. And, of course, the baby wakes up, and now to calm his unlikely…
I propose a simple addition to the doorbell. Just say that it’s good for calls that are switched through the circuit of 220 V. Here we need a cartridge with a bulb and the switch. Everything is connected as shown in the figure. In normal mode when you press the button is actuated and a bell, and a lamp in the “quiet” — only lamp.
I. GALKIN, engineer
Recommend to read
WITHOUT ALTERATION OF THE POWER SUPPLY
In Amateur radio practice, there are situations when 9-volt DC source you need to obtain 12, and then a higher output voltage. Bail in such cases can I designed a compact transformerless...
ONE-WHEELED TRACTOR
Compactness, maneuverability and good traction — the undoubted advantages of the one-wheeled tractor created at the station of young technicians in the city of Novotroitsk. They managed...
