TREE

As electrolytic capacitors age, their internal resistance, also known as "equivalent series resistance" (ESR), gradually increases. This can eventually lead to equipment failure. Using this design, you can measure the ESR of suspect capacitors as well as other small resistances. Basically, the circuit generates a low-voltage 100kHz test signal, which is applied to the capacitor via a pair of probes. An op amp then amplifies the voltage dropped across the capacitor’s series resistance and this can be displayed on a standard multimeter. In more detail, inverter IC1d is configured as a 200kHz oscillator. Its output drives a 4027 J-K flipflop, which divides the oscillator signal in half to ensure an equal mark/space ratio. Two elements of a 4066 quad bilateral switch (IC3c & IC3d) are alternately switched on by the complementary outputs of the J-K flipflop. One switch input (pin 11) is connected to +5V, whereas the other (pin 8) is connected to -5V. The outputs (pins 9 & ...

Circuit diagram Position Range a 1 uf b 100 nf c 10 nf d 1 nf e 100 pf Use X10 switch to measure up 10uf. Use X0.5 switch for better readings on low values. This project is more complex than the others described earlier. However, when finished, you will have an instrument capable of measuring all but the largest capacitors used in radio circuits. Unlike variable resistors, most variable capacitors are not marked with their values. As well, the markings of capacitors from salvaged equipment often rub off. By being able to measure these unmarked components, this project will prove useful to the constructor, vintage radio enthusiast or antenna experimenter. The common 555 timer IC forms the heart of the circuit (Figure Three). Its function is to charge the unknown capacitor (Cx) to a fixed voltage. The capacitor is then discharged into the meter circuit. The meter measures the current being drawn through the 47 ohm resistor. The 555 repeats the process several times a second, so that the ...

This circuit was designed to assist the installation of TV antennas. The signal is monitored using a small portable TV set and this circuit monitors the output of the TV's FM detector IC via a shielded lead. To initially calibrate the meter, adjust trimpot VR2 to zero the meter. Trimpot VR1 is a sensitivity control and can be set for a preset reading (ie, 0dB) or can be calibrated in millivolts. Rotating the antenna for a minimum reading on the meter (indicating FM quieting) gives the optimum orientation for the antenna. Circuit diagram: TV Relative Signal Strength Meter Circuit Diagram Author: Ted Sherman Copyright: Silicon Chip Electronics

Build a simple Capacitance to Voltage Meter Circuit Diagram . In this volt meter circuit uses timer Ul operates as a free-running oscillator at 60 Hz, providing trigger pulses to timer U2 which operates in the monostable mode. Resistor Rl is fixed and capacitor Cx is the capacitor being measured.   Capacitance to Voltage Meter Circuit Diagram While the output of U2 is 60 Hz, the duty cycle depends on the value of Cx. U3 is a combination low-pass filter and unity-gain follower whose dc voltage output is the time-averaged amplitude of the output pulses of U2, as shown in the timing diagram. The diagram shows when the value of Cx is small the duty cycle is relatively low. The output pulses are narrow and produce a lower average dc voltage level at the output of U3.  As the capacitance value of Cx increases, the duty cycle increases making the output pulses at U2 wider and the average dc level output at U3 increases. The graph illustrates capacitance values of 0.01 ?¥ to 0.1 ...

Volt meters & ampere meter with PIC can be used to measure voltage and current simultaneously. The series of volt meters & ampere meter with PIC16F876A PIC is used as a data processor voltage and current are measured.  This circuit uses the viewer in the form of 16 × 2 LCD used for the data menmpilkan voltage and current measurements. In the article volt meter and ampere meter with PIC are discussed kerannya limited to devices only. More detail can be seen from the image sequence volt meter and ampere meter with PIC below.  The images of Volt Meter & Ampere Meter With PIC Circuit Volt meters & ampere meter with PIC  

Minimalist Dip Meter Circuit Diagram. In days gone by a radio amateur always had a dip meter close to hand in his ‘shack’. Now that people can afford oscilloscopes, the poor old dip meter has lost its importance and is  frequently no longer to be seen. Actually this is a shame because many tasks are much easier to carry out with a dip meter. Anyone who’s interested (perhaps the second time around) can easily build one rapidly with this very simple but adequate circuit. The interesting question is namely what do you actually need from a dip meter? Minimalist Dip Meter Circuit Diagram Minimalist Dip Meter Circuit Diagram A visual display of the dip? Nope, the ‘scope can handle that task. A large frequency scale? Not necessary, as you can connect a frequency counter for this. A selection of coils? We don’t need these because we can use a jumper to change range (no coils to lose any more!). The sensor coil L1 has ten turns and is wound  using an AA-size battery as a former. This...

This circuit is used to measure the current from a solar panel. It has very low power loss for currents in the 0-10A range. It also works as a general purpose DC current meter. The circuit can be used on either the positive or negative side of a DC circuit. Solar Panel Current Meter Circuit Diagram Specifications Measured Current: 0-10 Amps DC, can be increased by changing the resistors. Circuit Voltage: Will work with DC circuits at any practical voltage. Accuracy: approximately 2% with a high quality meter movement. Theory The current to be measured flows through the 0.01 ohm resistor, this causes a small voltage drop across the resistor. 10 amps of current will produce a 100mV voltage across the resistor. The 100 microamp meter is wired in series with a 50 ohm fixed resistor and a 500 ohm variable calibration resistor so that it can measure the voltage drop. The 500 ohm variable resistor is used to adjust the meter's full scale reading. The 50 ohm resistor limits the maximum cur...

Here is a Simple LED Volt meter to Monitor the charge level in Lead Acid Battery or Tubular battery. The terminal voltage of the battery is indicated through a four level LED indicators. The nominal terminal voltage of a Lead Acid battery is 13.8 volts and that of a Tubular battery is 14.8 volts when fully charged. The LED voltmeter uses four Zener diodes to light the LEDs at the precise breakdown voltage of the Zener diodes. Usually the Zener diode requires 1.6 volts in excess than its prescribed value to reach the breakdown threshold level. When the battery holds 13.6 volts or more, all the Zener breakdown and all LEDs light up. When the battery is discharged below 10.6 volts, all the LEDs remain dark. So depending on the terminal voltage of the battery, LEDs light up one by one or turns off. Circuit diagram:  LED Volt Meter Circuit Diagram Author: D. Mohan Kumar Copyright: electroschematics.com