Here the simple traffic light controller which is could be used to educate kids rudiments of traffic light guidelines. The circuit utilizes easily available electronic parts. It generally consists of rectifier diodes (1N4001), a 5V regulator 7805, two timers circuit using IC 555, two relays (5V, single-changeover), three 15W, 230V light bulbs and also several discrete parts. Mains electrical power is stepped down by transformer X1 to provide a secondary [...]
This is the door bell circuit with flashing LEDs to make the circuit more attractive. IC1 (NE555) is applied right here as being a clock generator. It is actually set up as an astable multivibrator whose frequency could be altered using the support of potensiometer VR1. The clock pulses received from IC1 are fed to pin 14 of IC2 (CD4017) that is a popular decade counter circuit module.
This is a portable, 230V high-power incandescent electric lamp flasher circuit diagram. It is actually basically a double flasher (alternating blinker) which could manage two different 230V AC loads (bulb lamps L1 and L2). The circuit is completely transistorised and battery-powered. The free-running oscillator circuit is realised working with two low-power, low-noise transistors T1 and T2. One of these two transistors is constantly conducting, whilst the other is blocking. Because [...]