You can easily activate the LED from home electrical power line with this circuit diagram. You just need to add a nonpolar capacitor and a 1Kohm / 1W metal oxide resistor to activate the LEDs from home power line with serial connection.
A well-known IC LM35 is chosen to be the temperature sensor in this circuit. Output voltage of LM35 will increase by 10mV per degree rise in temperature. Output of LM35 is joined to the non inverting input of the operational amplifier (op-amp) of CA3130. The inverting input of the same op-amp could be provided using the required reference voltage using variable resistor R2.
This is the LED pilot light (or LED indicator) circuit. LEDs (Light Emitting Diode) part are interesting things. They only operate at DC supply within specific tolerances, and generally connected with a current limiting resistor towards the power source. Rather than a resistor, it is possible to use a FET (Field Effect Transistor) like the… Read More »
The following is LED Flasher circuit which use 2 transistors for LED switching. The circuit works similar to flip-flop operation. Components List: R1 = 10M ohm R2 = 1K – 100K ohm R3 = 470 ohm C1 = 0.47uF – 10uF/25V D1 = 1N914 Q1 = 2N3904 Q2 = 2N3906 Led = High Brightness Red… Read More »
The following image is the scheme diagram of six LED stereo VU display circuit which build using Dot/Bar Display Driver IC LM3915. This VU display should be connected before amplifier module circuit. You may connect this circuit at pre-amp output, tone control input/output or equaliser input/output. This circuit powered with 12V DC supply. About LM3915:… Read More »
This is a 220V LED flasher circuit which is intended as a reliable replacement to thermally-activated switches used for Christmas tree lamp-flashing. This a low cost circuit and easy to built since it only use little amount of electronic components.. Schematic diagram: Component Parts: R1_________ 100K R2,R5______ 1K R3,R6______ 470R R4_________ 12K C1_________ 1000uF 25V… Read More »
This is a very easy and simple LED flasher with only three components: a flasher IC LM3909, a LED indicator and an electrolytic capacitor. The supply voltage is 1.5V, so it can be operated using a 1.5V battery which can be easily found on market. Component list: LED1 _________ Red LED C1 ___________ 100uf/16V IC1… Read More »
This is the circuit of LED color fade effect. Just like the name of the circuit, the light intensity of LEDs in this circuit will fade from high intensity to low intensity and then off. Here the final result preview:
This is running LEDs circuit which use timer ID NE555N and logic IC 4017N. IC 555 act as a multivibrator and generate frequency to be used for 4017 clock input.