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Expanded-scale indicator revisited - 08/08/02 EDN Design Idea The visualization aid that a previous Design Idea describes
allows only the expansion of the upper end of the scale (Reference 1]. But what can you do if, according to
your project requirements, you need to expand the middle region o. . . [by Abel Raynus, Armatron
International Inc, Melrose, MA]
Expanded-Scale Voltmeter Uses Just Two Parts - 01/20/94 EDN Design Idea The expanded voltmeter doesn't require trimpots to obtain usable
accuracy or require the tedious selection of Zener diodes. This circuit consists of only two parts and a5V
meter. The circuit is completely linear and requires no . . . [by DD Cantrell, North Valley Research, Los
Molinos, CA]
Four Channel Digital Voltmeter with Display & Keyboard - Application Note Published 27-May-05. . . [Microchip]
High Impedance Voltmeter - This circuit is designed to provide an inexpensive way to to create a High Impedance
Voltmeter while making use of an inexpensive analog or digital multimeter. The circuit is specifically
designed for testing phototransistors when they are used in the circuits shown at this site. It has a very
high input impedance that will not "Load Down" the sensor that is being checked. . . [from Rob Paisley's
Model Train web site]
High-impedance voltmeter - An ideal voltmeter has infinite input impedance, meaning that it draws zero current from
the circuit under test. This way, there will be no "impact" on the circuit as the voltage is being measured.
The more current a voltmeter draws from the circuit under test, the more the measured voltage will "sag"
under the loading effect of the meter, like a tire-pressure gauge. . .
ICL7107-DigitAL LED VOLTMETER - This digital voltmeter is ideal to use for measuring the output voltage of your DC power
supply. It includes a 3. 5-digit LED display with a negative voltage indicator. It measures DC voltages from
0 to 199. 9V with a resolution of 0. 1V. . . .
LED display Digital Voltmeter - This digital voltmeter is ideal to use for measuring the output voltage of your DC power
supply. It includes a 3. 5-digit LED display with a negative voltage indicator. It measures DC voltages from
0 to 199. 9V with a resolution of 0. 1V. The voltmeter is based on single ICL7107 chip and may be fitted on a
small 3cm x 7cm. . .
LED Voltmeter Expanded Scale
(ideal for your car) - Its Useful to see the charge
voltage. This Helps in detecting a Bad Alternator before it creates a dead battery. . . . [G.L. Chemelec,
designer]
LED Voltmeter Expanded Scale
(ideal for your car) - Its Useful to see the charge
voltage. This Helps in detecting a Bad Alternator before it creates a dead battery. . . [G.L. Chemelec]
LED Voltmeters 20 & 30 LED's - Both Can be Switched to Bar or Dot Displays. . . . [G.L. Chemelec]
Logic Gates Form High-Impedance Voltmeter - 05/26/11 EDN Design Idea Estimate voltages across high-value resistances. You can use
the circuit described in this Design Idea to estimate voltages across 10- to 100-MΩ resistances. It also
works for reverse-biased diodes. The common CMOS gates in Figure 1 have an input threshold voltage in which
the output swings from logic zero to logic one, and vice versa. The threshold voltage depends on the supply
voltage (Figure 2). . . . [by Raju R Baddi, Tata Institute of Fundamental Research, Maharashtra, India]
Low Power LED Voltmeter - This is a low power voltmeter circuit that can be used with alternative energy systems that
run on 12 and 24 volt batteries. The voltmeter is an expanded scale type that indicates small voltage steps
over the 10 to 16 volt range for 12 volt batteries and over the 22 to 32 volt. . . [G. Forrest Cook]
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