Testers or Instruments electronic circuits, beginning with #'s

Tester or Instrumentation Circuits, Page 1
Testers: #'s A-B C D E F-G H-K L M-O P Q-R S T U V-Z

Last Updated on: Friday, March 12, 2010 12:07 PM

Circuits Designed by Dave Johnson, P.E. :

1 AMP CURRENT INJECTOR
When you need to measure resistance down to a few micro ohms, this circuit works great. It is powered from two "C" cell batteries and is designed to inject a well-regulated one amp of current into the unknown resistance. By measuring the voltage drop across the resistor with a digital voltmeter, the resistance value can be accurately measured. The circuit also is equipped with a low battery monitor. Published in Popular Electronics, November 1992

120vac Under Voltage Tester
Using a cheap 24vac transformer, this circuit can test a product under low 95vac conditions. With the components show, it has a rating of 250 watts max.

20MHz VCSEL 3mW LASER TEST CIRCUIT
This circuit takes advantage of some new vertical cavity surface emitting lasers (VCSEL) that don’t require light output control circuits. The circuit shows how to drive the device from a single high speed CMOS IC. The circuit can easily be modified to transmit signals from kilohertz to about 50MHz.

40KHZ LED TEST SIGNAL GENERATOR
This 40KHz crystal controlled oscillator circuit drives an infrared LED with powerful 40ma pulses. The circuit can be used to test optical communications circuits, designed to receive 40KHz modulated light signals.

Links to electronic circuits, electronic schematics, designs for engineers, hobbyists, students & inventors:

$5 junkbox Circuit Determines Phase Sequence - 04/23/98 EDN-Design Ideas: [Note: File contains multiple circuits scroll to find this circuit.] Have you ever wondered which way a blower motor is going to turn when you plug it into anor socket, or have you ever inherited task of modifying three-phase wiring in your plant?.....(design idea added 11/05)

µC measures High frequency signals - 03/02/98 EDN-Design Ideas: (design idea added 6/06)

0-50V 2A Bench power supply Circuit - ….(design added 08/08)

1 Amp Current Injector - When you need to measure resistance down to a few micro ohms, this circuit works great. It is powered from two "C" cell batteries and is designed to inject a well-regulated one amp of current into the unknown resistance. By measuring the voltage drop across the resistor with a digital voltmeter, the resistance value can be accurately measured. The circuit also is equipped with a low battery monitor. Published in Popular Electronics, November 1992 ….(designed by David A. Johnson)

10 Amp 13.8 Volt Power Supply - Just like other commercial units, this circuit uses the LM723 IC which gives us excellent voltage regulation. The circuit uses 3 pass transistors which must be heat sinked….(electronic design added 6/07)

10 Hints for Making Better Network Analyzer Measurements - Aligent App Note (app note added 6/07)

10 Practical Tips You Need to Know About Power Products 5965-8239E - Learn ten simple ways to improve your testing capabilities with your power supplies and electronic loads. Aligent Application Note (app note added 2/06)

10Hz - 100kHz D.D.S. Function Generator - (electronic circuit added 05/07)

10Hz - 1300MHz Frequency Meter - Universal VHF/ UHF frequency meter (circuit added 8/06)

120vac Under Voltage Tester - Using a cheap 24vac transformer, this circuit can test a product under low 95vac conditions. With the components show, it has a rating of 250 watts max. ….(designed by David A. Johnson)

13.8V 20A PSU - This is a Regulated DC power supply with short circuit protection and with current limiter. (electronic design added 6/07)

16-Bit ADC Simplifies Current Measurements - DN341 Design Notes (Linear Technology) (app note added 6/06)

2 GHz Frequency Counter - This simple counter is useful for frequency measurements of various wireless equipments, especially transmitters, receivers and signal generators in VHF/UHF band…(circuit added 8/06)

20MHz High Speed Function Generator - The High Speed Function Generator was published in the professional electronics section of the Aug 1996 issue of Electronics Australia, and has proven to be extremely popular. The kit is no longer available from any of the kit suppliers. The project is capable of generating 20MHz or greater Sine, Square, Triangle, and TTL waveforms. ….(electronic schematic added 11/08)

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