This is the cell phone shield circuit which can be used as mobile charger. Give protection to your cell phone from unexpected use or theft working with this easy circuit. It is able to produce a loud chirping sound when someone tries to take away the mobile handset. The added function is that the circuit… Read More »
The following diagram is a simple mobile phone battery charger circuit. The design is simple, easy to build and inexpensive. It use LM78xx regulator to make regulated and stable output voltage. Mobile phone chargers offered in the marketplace are quite expensive. The circuit shown right here shows up as a low-cost option to charge cell… Read More »
This is the fire alarm circuit which use LDR to sense the smoke from the fire, so it can be used to detect any dark smoke. With the onset of summer season, possibilities of fire accidents go up. These fire accidents could be prevented if timely alarms are available. The circuit given right here alerts… Read More »
This is a low-cost and simple intercom circuit design. Some intercom circuits is build by applying integrated circuits. The circuit described right here utilizes 3 certainly transistors which easy to find on the electronic store. Even a newbie can assemble it on a piece of veroboard without difficulty. The circuit consists of a 3-stage resistor-capacitor… Read More »
Here is the schematic design of car cigar lighter to USB power port. Nowadays, almost all computer systems have logic blocks for working with a USB port. In practice, a USB port is capable of supplying more than 100 mA of continuous electric current at 5V to the peripherals which are hooked up with the… Read More »
This is the circuit diagram electronic door lock security key system. It means that this security system circuit is the combination of pressed key itself (not the mechanical). The output can be connected to drive the relay to open the door (usually using motor).
Here the Arduino UNO schematic diagram (click to enlarge): About Arduino UNO: The Arduino Uno is really a microcontroller board based on the ATmega328. It has 14 digital input/output pins (of which 6 may be employed as PWM outputs), 6 analog inputs, a 16 MHz crystal oscillator, a USB connection, a power jack, an ICSP… Read More »
The following diagram is an inverter circuit which will give you 220V AC 50Hz with maximum power output of 100W. This inverter built using transistors for both the square wave generator module and the amplifier module. Inverter Diagram: The Q1 and Q2 used generate square wave. Q5-Q8 amplify the signal and the transformer to increase… Read More »
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.