Circuit diagram

This circuit has a voltage output of about 12 volts with 20mA current voltage. And this series of works using capacitive reactance and resistance are not using, this will reduce the heat on the circuit.


To be safe when there is a short-circuit series, always use a fuse on the input voltage is 220V. Here is a series of power supply without a simple transfomer.

A unpretentious audio amplifier circuit can happen designed using the LA4460 IC . This circuit is very simple and require little exterior electronic components . The LA4460 IC is in fact used on behalf of car broadcasting or else car audio power amplifier and could provide output power up to 12 W. But at home this circuit is solitary used 5W.

This amplifier circuit can come about used for car means of communication applications , small screen , or else around other audio circuits so as to don’t require vast power .

explanation:

Many SWR / Power meter used by amateurs to the extent reasonably accurate continuous average power with a CW key-down signal, but can not reliably be used with other (modulated) signals PEP or average power measurement. These laws seek to show why the power measurement can be a sensitive issue, and because the interpretation of a yardstick of power can be a lot of attention and knowledge of construction and the characteristics of the instrument.

A reflectometer-type SWR meter can be calibrated to give power back and forth (PF, Pr) on a power supply. A classic example is the 1943 Bird Series power meter, which is a directional coupler is used to obtain a sample voltage proportional to the voltage wave or forward or backward on the feeder (VF, VR). Other systems, perhaps more suitable for HF, then use a bridge circuit to perform the same function.

 Simple SWR and PWR Meter Circuit diagram 


The sample voltage is then rectified and displayed on a meter that is calibrated in watts. If the counter is typically a coil, the scale, so the numbers on the scale, representing the power, are proportional to the square of the applied voltage or the current calibration. The theory of this type is very simple and is based on the concept represented by PF = Vf2/Zo. Note that if the power supply has an impedance that differs from the value of how the instrument is calibrated, there will be a mistake. The output voltage of the rectifier is a solid phase of VF or VR, and this is expected in the calibration of the meter.

Examples of directional coupling, and bridge-type reflectometers are shown in Figures 1 and 2, while the bird directional coupler means 43 is illustrated in Figure 3. Note that in all cases the measurement circuit, a combination with a small RC time constant, making the system unsuitable for the measurement of PEP, and the absence of a specific device quadratic, making them unsuitable for measuring the average power .

Accu charger circuit is very simple and easy to make, because it only requires a few components are also not more than 10 components. Besides easy charger circuit is also very cheap and very efficient. 

This circuit requires power supply from a transformer that comes from an AC voltage 220 ​​and diuturunkan be 12-13 volts and then enter to-circuit and 12 Volt DC output allows for charging 12V ​​battery

This circuit is used to save electricity in our homes to avoid spending too much . How it works ? This circuit of works to filter the AC voltage , and reduce the magnitude of the cosine curve AC current that will be read on the instrument KWH meters. KWH meters will work if there is a load wire passing through a coil of wire sensors to measure the AC current is passed, if the current through a lot of electricity. C1 and C2 worked as a deduction from stamping voltage if the switch is connected, so that equipment or components which enter the voltage was not much shocking.

Part List :
C1,C2 = 100pF / 400V or higher
C3      = 10uF / 400V non polar capacitor
Fuse   = 0.5W
S1      = Switch on/off
Use best quality capacitors

Use the circuit on each item that requires AC power house to besaved using voltage field of electronics goods. Or if you take the trouble to make on each item , then use immediately near the KWH meter, to disconnect to tke their input and issued again on output, should use the box to close the circuit.

I got this Idea from this useful site here

Simple fm transmitter for the experiment. This designation may be appropriate to call this series, because rangkaianya very simple and suitable for learning / beginners. and preferably when assembling, which assembled its first part oscilator. then we try it first. if able to function normally, we can proceed to the next level up to the booster. for the scheme and a list of components please download here.

In this section discuss about the series of mini fm transmitter, with broadcast coverage of about 300-400 meters. when using a 9 volt working voltage, the transmit power of about 300 meters and when using the working voltage 12 volts, the range of about 400-450 meters, depending on the antenna you use.

Normally analogue-to-digital con-verter (ADC) needs interfacing through a microprocessor to convert analogue data into digital format. This requires hardware and necessary software, resulting in increased complexity and hence the total cost.

The circuit of A-to-D converter shown here is configured around ADC 0808, avoiding the use of a microprocessor. The ADC 0808 is an 8-bit A-to-D converter, having data lines D0-D7. It works on the principle of successive approximation. It has a total of eight analogue input channels, out of which any one can be selected using address lines A, B and C. Here, in this case, input channel IN0 is selected by grounding A, B and C address lines.

Simple Analog to Digital Converter Circuit diagram


Usually the control signals EOC (end of conversion), SC (start conversion), ALE (address latch enable) and OE (output enable) are interfaced by means of a microprocessor. However, the circuit shown here is built to operate in its continuous mode without using any microprocessor. Therefore the input control signals ALE and OE, being active-high, are tied to Vcc (+5 volts). The input control signal SC, being active-low, initiates start of conversion at falling edge of the pulse, whereas the output signal EOC becomes high after completion of digitisation. This EOC output is coupled to SC input, where falling edge of EOC output acts as SC input to direct the ADC to start the conversion.

As the conversion starts, EOC signal goes high. At next clock pulse EOC output again goes low, and hence SC is enabled to start the next conversion. Thus, it provides continuous 8-bit digital output corresponding to instantaneous value of analogue input. The maximum level of analogue input voltage should be appropriately scaled down below positive reference (+5V) level.

The ADC 0808 IC requires clock signal of typically 550 kHz, which can be easily derived from an astable multivibrator constructed using 7404 inverter gates. In order to visualise the digital output, the row of eight LEDs (LED1 through LED8) have been used, wherein each LED is connected to respective data lines D0 through D7. Since ADC works in the continuous mode, it displays digital output as soon as analogue input is applied. The decimal equivalent digital output value D for a given analogue input voltage Vin can be calculated from the relationship

This Field Strength Meter is simple and also quite sensitive. It uses an ordinary digital voltmeter to measure RF signal strength up to a few hundred MHz.



Simple Field Strength Meter Circuit diagram:




Parts List:

1 OA91 Germanium Diode
1 3.3M Resistor
1 100p Capacitor
L1 7 turns on a 1/4 inch former (suitable for around 100MHz)

Notes:

The multimeter should be set to the lowest dc volts range for maximum sensitivity. This is normally 200mV DC for most meters. The circuit works well at VHF (around 100MHz) and was quite pleased with the results. L1 was 7 turns on a quarter inch former with ferrite slug. This covered the UK FM band.

A digital multimeter, as opposed to an analogue signal meter offers several advantages in this circuit. First, the impedance of a digital meter is very high, around 10Meg/Volt on most meters. This does not shunt the tank circuit unduly. Second, compared to an analogue meter, very slight differences in signal strength can be more easily observed. Thirdly,a digital meter will have better linearity, responding well to both weak and stronger signals.

A very simple audio mixer can be designed using this circuit diagram electronic project. Audio mixing is normally performed by a mixer with virtual ground, in which the various input signals are applied through series resistors to virtual ground, that at the inverting input of operational amplifier. 

The audio mixer is a little different and uses the principle of common ground, the input voltages are converted into alternating current which, when summed, is the AC component of the collector. In the case of a common base configuration, emitter impedance is small and works as a virtual ground that is making it impossible to crosstalk between different input signals. The output signal is taken from the collector of Q1. Amplification circuit is equal to R6 + Ri, where Ri is the input resistance (= one of the resistances RI ... R5). The T1s emitter circuit has been provided a power source consisting of T2 and T3.

Q1s base voltage is set by resistors R7 and R8. Ensure that the capacitor C1 of T1 to be effectively disconnected.

A very simple proximity detector electronic project can be designed using this schematic circuit . This proximity detector electronic project use a tone decoder integrated circuit ( NE567 ) that will provides a signal with a frequency about 100Khz . This signal is fed to one sensor . The sensor can be constructed from two cooper or aluminum plates or wires or other conductive material .

Simple Proximity Detector Schematic Circuit Diagram

When an object is placed near the sensor , the capacitance between sensor is increased . The Q1 and Q2 transistors will amplify the signal and fed it to the NE567 IC , that will make the LED1 to glow . C8 and R4 phase shift the VCO signal from the NE567 so that the U1 can detect its own output signal .

This electronic project circuit require a 9 volts DC power supply circuit .

This simple Door Chime protects the door and gives a loud Alarm tone when there is an attempt of theft. The circuit is too simple and battery operated. A Normally Closed (NC) reed switch and magnet is used to trigger the circuit. Alarm generator is the popular ROM IC UM 3561. This 8 pin IC has an inbuilt oscillator to generate 4 siren tones like, Ambulance siren, Police siren, Fire brigade siren and Gun sound. The different tones can be selected using its pin 6 connected to VCC, Ground or not connected. Frequency of oscillation is determined by the 220K resistor connected to the pins 7 and 8 of the IC.UM 3561 is the low power IC and its maximum voltage rating is 3 volts. So Zener diode ZD is used to give 3 volts supply to IC. Medium power NPN transistor T1 amplifies the output pulses from IC1 to a loud siren.

Tiny Door Guard Circuit diagram:




Magnet can be a small sized one that is to be fixed in the door using double sided adhesive tape. Fix the circuit board in the door frame. Fix Reed switch in the door frame, very close to the door. So that, when the door is closed, the magnet will pull the contacts of the reed switch to break supply to the IC. When the door opens, contacts of the reed switch make contact and IC gets power to give alarm.