The article points out a straightforward digital panel type voltmeter circuit utilizing a single IC L7107 and a couple of other normal parts. The circuit has the capacity to calculate voltages right up to 2000 AC/DC V.
Providing this easy digital panel voltmeter circuit is especially hassle-free on account of the access of the A/D voltage processor chip by means of IC L7107.
As a result of Intersil for offering us with this particular wonderful little IC L7107 which is often very easily set up into a wide range digital voltmeter circuit making use of a couple of number of popular anode seven segment displays.
The IC 7107 is a flexible, low consumption 3 and 1/2 digit A/D converter IC which includes in-built processors for example seven segment decoders, driver for displays, set reference levels and clock generators.
The IC not just works together with regular CA seven segment displays but additionally with liquid crystal displays (LCDs) and has an in-built multiplexed back plane illuminator for the associated LCD module.
It guarantees auto zero correction for inputs lower than 10uV, a zero drift for inputs below 1uV/oC, bias current for inputs of highest 10pA and cross over error of less than a single count.
The IC might be set with ranges as much as 2000 V AC/DC, and as low as 2mV, the in the future tends to make the IC very well suited for calibrating low inputs from sensors like load cells, piezo transducers, strain gauges and comparable bridged transducer networks. To put it differently, te chip could be merely designed to make equipment like digital weighing scale, pressure meters, electronic strain gauge, vibration detector, shock alarms a lot of equivalent circuits.
As you can imagine, the IC L7107 may be as well rigged into a basic yet precise panel digital voltmeter circuit, which can be what we are currently thinking about.
Talking about the circuit diagram below, the unit is a complete fledged digital voltmeter circuit that are available for calculating direct voltages starting from zero to 199 volts. The range could be properly broadened or hardened easily by changing the value of the 1M resistor placed in series with the input terminal. With 1M, the choice offers a full scale of 199.99V, with 100K in place the range would certainly turn into 19.99V full scale.
The circuit needs a dual +/-5V supply for working, right here the +5V might be totally obtained from a regular 7805 IC regulator circuit, the -5V is instantly produced by the IC 7660, and fed to pin#26 of the IC L7106.
The three 1N4148 diodes attached in series with the display supply line guarantees optimal running voltage to the displays for lighting them with proper strength, in spite of this for brighter illumination, the number of diodes could be experimented, according to desires and demands.
The 10K preset across pin#35/36 is utilized for calibrating the voltmeter properly and ought to be set such that precisely 1V seems across pin#35/36. This may establish the circuit for exhibiting the calculated magnitudes precisely based on the presented specifications, and datasheet of the IC.
Pinout information of IC L7106 for interfacing with a 3 and 1/2 digital LCD display.