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.
Here the circuit diagram of musical bell with touch switch and timer. This circuit is designed around CMOS IC CD4011 which work as the delay timer and IC UM66 which is well-known musical sound generator. When touch plates are bridged (touched) by hand for a moment, the circuit will start to produce music sound. Just after a short period (few seconds), the musical sound from this circuit will automatically stop.
This is the design diagram of electronic jam. This jam circuit can be implemented in quiz contests in which any participator who pushes his switch (button) prior to the other participants, will get the first opportunity to answer a question. The circuit provided right here allows up to eight participants with each one assigned a unique number (1 to 8). The display will show the number of the contestant pushing [...]