Meters

Quick view of Square wave oscillator as wire tracer

The tracer works by placing a square-wave signal ?n the line to be traced, The square wave is full of harmonics. ? small radio placed close to a wire carrying this signal will buzz. The radi?, therefore, is used as a probe to trace out the wire...

Car Voltmeter Circuit

Car Voltmeter Circuit

This screen uses ten LEDs to display a voltage range of 10.5 to 15 volts. Each LED represents a step 0.5wvolt tension. The heart of the circuit is the 3914 points LM / bar display driver. Trimming potentiometer R5 is adjusted so that 7.5 volts is applied to the upper side of the bulkhead. D2 resistor R7 and diode D5 to tighten the voltage applied to the LED 3 volts. A lowpass filter consisting of L1 and C2 guards against voltage spikes. The diode D1 is used to protect against reverse voltage where the voltmeter is connected backwards. ..

LED Battery indicator

LED Battery indicator

This battery allows the indicator to the car battery voltage monitor. The indicator has four LEDs which indicate power. The more LEDs, the higher the voltage. The last LED is a flashing LED. It comes on when the accuspaning limit of about 15 V limit. This is a sign that something is wrong with the alternator or voltage regulator. The other LEDs light up in 9 V (D5: bad battery), 11 V (D7: battery doubtful) and 13 V (D9: battery ok). Build the circuit and verify the above activation points. If the measured values ??much different from the above, try other Zener diodes. Of 300 mW Zener are sufficient for the circuit...

Fuse tester with LEDs

Fuse tester with LEDs

This indicator shows through a dual-LED see if a fuse is intact. The module is designed for 230 V AC. The green LED illuminates when the fuse is still good, the red lights when the fuse is broken. Perhaps the circuit to adjust for other voltages by changing the value of R1...

Analog Volt and ampere meter

Analog Volt and ampere meter

For those who labvoeding built and flow of tension and a leader in providing circuit below was developed. If meter is a moving-coil meter 100?A useful. You have to make yourself a new scale. Also useful is a moving coil meter Conrad sells. This meter has already graduated to 30V and 1.5 A. S1 can be omgechakeld between volts and current measurement...

Transistor Tester with LEDs

Transistor Tester with LEDs

This transistor has only one IC tester and can test all types of transistors. With two LEDs indicating the type of the transistor is NPN or PNP. The circuit uses a CMOS 4049 IC. The test transistor to terminals "B" "C" and "E" attached. Then when the power is turned on, a transistor with a good LED flash. Both LEDs flashing lights or not, the transistor is broken. ..

Transistor tester schematic

Transistor tester schematic

This is a convenient design for a transistor tester. The advantage of this circuit is that transistors can be tested without actually doing the circuit soldering. The tortester uses two ICs: an NE 555 timer and a CMOS IC 4027. In 4027 there are two flip-flops. The timer generates a square wave of about 12 Hz. IC2 through the square wave then used to test the transistor. ..

Thyristor / TRIAC Tester

Thyristor / TRIAC Tester

This is a simple but effective and thyristor TRIAC Tester. Operation at a good thyristor / triac: LED lights when SW3 is pressed. LED turns off when SW2 is pressed. If this occurs, the thyristor / triac OK. Tip: Hirschmann clips for the tested thyristor / triac connecting, including this quotation terminals. The supply voltage is 9V, with a minimum current of 400mA. ..

Analogue Ohm meter

Analogue Ohm meter

This is a simple ohm meter that is small to build. The circuit operates with a constant current around T1. The current depends on the emitter through S1 can be chosen. These are the ranges of the meter. The constant current through T1 causes a voltage drop across Rx, the measured resistance. This voltage is measured by M. D2 is a germanium diode. You can try a 90 or OA 118 using AA. The resistance value is the range times the meter reading in volts...

LED tester circuit

LED tester circuit

This ledtester uses as a power switched opamp. The control range is about 0-30mA. Thus, all test and standard LEDs, the voltage across the LED to read. The power supply is an example labvoeding at least 15V, 12V adapter if you're a U2 expires. Then put a jumper between pins 1 and 3 and use a 10uF electrolytic capacitor for C1. The LM358 is only half used the other half to the mass shut down. ..

Audio conductivity tester with LM3909

Audio conductivity tester with LM3909

This works with a small geleidingstestertje LM 3909. It allows a tester beeps when the resistance between the probes between 0 and 100 ? lies. Due to the volume of the beep, the resistance between the probes can be determined...

Zener Tester schematic

Zener Tester schematic

With this simple measuring device can: Determine the Zener voltage up to 25V. The connections of cathode and anode of each diode finding. Check if a diode fails. Silicon, germanium and Schottky diodes distinguish. LED test and the V forward measure Q1 is connected as power supply. Because D1 is a constant tension on the base and there is resistance in the chosen emitteraansluiting approximately 5.6 V. With an R2 emitter of 5K6 will run through the transistor than 1mA. ..

Conductivity Tester circuit

Conductivity Tester circuit

This little guide for every electronics tester would actually have to lie in the toolbox. You can have components such as resistors, capacitors, diodes, etc. of testing. T1 and T2 form a Darlington. Therefore only need a small base current to run and the LED is already lit. The tester is suitable for up to 2 M? resistors. The tester is also suitable for capacitors. When a capacitor is connected to the leads, the LED, depending on capacity, light briefly and then to extinguish. ..

Diode Tester schematic

Diode Tester schematic

With this tester you can check whether a diode is working properly. In the table you can see what LED to indicate the positions of the switch and condition of the diode. The circuit can be connected to a 9 V battery...

Hi-Low Logic Digital tester

Hi-Low Logic Digital tester

This tester, the logic level digital signals indicate on a 7-segment display. The display shows an H as the input signal is high. When the signal is low, the display shows an L on. If the input is open, the display shows N. The circuit consists of a TTL NAND IC type 74LS00 and three transistors. The NAND gates ensure that the right segments of the display can be controlled. ..