Turn your Digital Voltmeter into an Inductance and capacitance meter. Page 1. Page 2. Products 1 – 20 of 22 Source LCR Meter Accessories at ; the leading distributor of IT, Test Peak Electronic Design LLSm LCR Meter Adapter.
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The circuit relies on a voltmeter with a millivolt range and a high input impedance as a readout device, so it doesn’t have a buffer on the output.
The neter S2 is in position “C”. The pulse width that is proportional to the inductance is made by drving the unknown inductance through a resistor and connecting the resultant sawtooth waveform to the input of another schmitt trigger which, because of the sharp switching action on its output that results from its hysteresis, provides a nice rectangualr pulse.
Inductance and capacitance meter adapter for DVM
The source of the voltage is negative pulses across the inductance Lx. Potentiometer Questions Started by norbss Yesterday at It metet analyzes transistor’s characteristics such as voltage and gain. The voltage is negative. Here is the unit measuring a 33 uH commercial RF choke.
LC Connector adapter
There is a remote possibility that you are using a damaged 74HC14, but check this last since it isn’t very likely. This circuit is only accurate for broadband inductors. At aeapter, adjust potentiometers R Real-Time ‘Stopwatch’ This is a simple electronic “stopwatch” you can use to time an event. The circuit includes an auto ranging as well as reset switch and produces very accurate and stable readings. I adapted it to the components Adaptwr had on hand and changed it so that it would work in the nanohenry to 50 microhenry range.
Connect a battery and a DVM digital volt meterput a known inductor in the LX position then adjust the potentiometer until you get the anticipated reading on the DVM.
I used it when developing a d. This circuit provides DC output voltage on the clamps X6, X7, and this voltage is directly proportional to the inductance of Lx. If you find the voltage to be very low, say under a volt, then this points to a wriing error, inductancd problem with the 5V regulator or the battery, a damaged 74HC14, or you are using a very low resistance voltmeter. More resources from carbonzit Resource icon.
Media New media New comments Search media. I calibrated my unit for uH, as this is the range I am generally most interested in, and it gives direct-readings on the uA scale of the meter. I had run across the forerunner of this circuit, one that is more sophisticated in that it has a zero adjustment and range switch, but it was limited to higher inductances. I needed a way to measure hand-wound RF inductors in my second lab, and since I would only be doing this occasionally, I didn’t need anything fancy, and since once a friend finishes his AT90Sbased design, I plan to make one myself, I figured I’d use this for less than a year, so I didn’t want to invest a lot of time in making it.
If you use a DIP, your life will be much easier. The transistor Q1 is used to amplify the signal to provide sufficient current through potentiometer R8 and a load circuit. Never mind, just adjust the oscillator frequency until you get it to calibrate. The pulse frequency is set by a schmitt trigger oscillator composed of a feedback resistance 2k pot and 3.
Author carbonzit Creation date May 25, This LC Meter allows to measure incredibly small inductances making it perfect tool for making all types of RF coils and inductors. If it isn’t, its probably because the thresholds on the 74HC14 are not symmetrically positioned around 2. When you built this, keep the connections, including gorund connections, emter because tens of nanoseconds count.
The switch S2 is in position “L”. Here are some things to check when calibrating: It’s small, power efficient, yet customizable through onboard 2 x 7 perfboard that can be used for connecting various sensors and connectors. Inductors with iron cores, high permeability ferrites, or with large amonts of shunt capacitance cannot be measured accurately. You can control lights, fans, AC system, computer, printer, amplifier, robots, garage door, security systems, motor-driven curtains, motorized window blinds, door locks, sprinklers, motorized projection screens and anything else you can think of.
Resource icon Inductance measuring adapter for multimeter The output waveforms can be meteg amplitude and frequency modulated.
Inductance and capacitance meter adapter for DVM
How the circuit works The schematic diagram for the inductance and capacitance meter is shown in Fig. It can be connected to any type of stereo audio source such as iPod, Computer, Laptop, CD Player, Walkman, Television, Satellite Receiver, Tape Deck or other stereo system to transmit stereo sound with excellent clarity throughout your home, office, yard or camp ground.
This RC network operates as adaptfr integrator circuit. Click here to register now. Simple Audio Signal Injector Here’s a signal injector for those of us like me who don’t have a aeapter full of nice test equipment. Just saying hello Started by MichaelaJoy Yesterday at 6: If yours runs at a greatly different frequency, try changing the oscillator components or try using a 74HC14 made by a different manufacturer.
This device is an addon to a digital or analog voltmeter. The hysteresis in the schmitt trigger allows it to oscillate with the simple feedback circuit.
I happned to have the 74HC14 in an SO package so I soldered it onto the metalized side of a prototyping board.