Testers or Instruments Electronic Circuits, beginning with C's

Tester or Instrumentation Circuits, Page 3b
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. :

CAPACITANCE TYPE LIQUID LEVEL MONITOR
This circuit was originally designed to monitor the level of liquid natural gas in a tank but it can be used to also measure almost any liquid. Two custom insulated metal tubes form a capacitor plate. The capacitance between the two tubes increases as the level of the liquid rises. The circuit converts an increase of capacitance into a positive voltage change. The circuit could be changed to handle almost any scale factor needed.

Cheap Electrostatic Discharge Tester
Anyone who has ever had a shocking experience on an especially dry day is acutely aware of the kinds of high voltage that can be generated from a simple walk across a carpeted floor. Those same finger to metal sparks can destroy or disrupt sensitive electronic circuits. Good design practices take great care to avoid such potential disasters by maintaining sufficient insulation between metal or plastic enclosure parts and the electronics within or by shielding any especially sensitive components....

Cheap Light Power Meter
Some time ago I was experimenting with the use of some low leakage photovoltaic solar cells, to harvest some energy from the diffuse lighting inside a room. The plan was to use a small array of solar cells (the type often used on solar powered calculators) to keep a super capacitor charged, drawing power from the light within an inside room...

Clear Fluid Detector #2
Using an ultra low power technique, this circuit detects when a clear fluid is inside a piece of clear plastic tubing. It can be used for fluid level control and monitoring.

Clear Fluid Detector
This circuit detects when a clear fluid is inside a piece of clear plastic tubing. It can be used for fluid level control and monitoring.

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

Circuit Monitors Multiple Contact Closures - 02/15/96 EDN-Design Ideas: (design idea added 3/03)

Circuit monitors quad supply for PCI systems - 08/19/99 EDN-Design Ideas: Many modern systems operate with multiple power supplies that must meet tight tolerances to accommodate high-end µPs and peripherals. For instance,.....(design idea added 6/06)

Circuit Produces a Less than 25 Nsec Pulse - 05/11/00 EDN-Design Ideas: (design idea added 6/06)

Circuit provides accurate RTD measurements - 04/12/01 EDN-Design Ideas:.....(design idea added 05/03)

Circuit Provides High Side Current Sensing - 04/24/97 EDN-Design Ideas: (design idea added 8/03)

Circuit Serves as Milliohm Meter - 04/15/04 EDN-Design Ideas: When I was recently debugging a design, I discovered that a short circuit existed from a ground plane to a power plane. I did not have access to a milliohm meter or an equivalent tester for locating this type of short circuit. So, I logged onto the Internet to find an easily constructible milliohm meter.....(design idea added 1/05)

Circuit tests VCOM Drivers - 11/11/04 EDN-Design Ideas:.....(design idea added 5/05)

Circuitry for Inexpensive Relative Humidity Measurement - National Semiconductor Application Note 04-Nov-1995 (app note added 6/06)

Circuitry for Inexpensive Relative Humidity Measurement - National Semiconductor Application Notes,04-Nov-1995 (added 1/03)

Clear Fluid Detector -2 - Using an ultra low power technique, this circuit detects when a clear fluid is inside a piece of clear plastic tubing. It can be used for fluid level control and monitoring. ….(designed by David A. Johnson)

Clear Fluid Detector-3 - This circuit detects when a clear fluid is inside a piece of clear plastic tubing. It can be used for fluid level control and monitoring. ….(designed by David A. Johnson)

Cloud Charge Monitor - The Cloud Charge Monitor is an extremely sensitive device capable of detecting subtle (and not-sosubtle) changes in the accumulated charge overhead. The device consists of a charge-sensing antenna, a 60 Hz notch filter, a self-zeroing integrator, a signal limiter, and a leakage zero adjustment....(circuit / schematic design added 04/05/06)

CMOS Logic Probe (Tony van Roon) - with probe, CMOS (Tony van Roon's electronic design added 4/02)

CN-7: Testing of COP400 Family Devices - National Semiconductor Application Note (app note added 2/06)

Coax connectors make Low cost test pieces - 06/22/00 EDN-Design Ideas: (design idea added 2/06)

Comparison of Leading Switch/Measure Solutions - Agilent Application Note (added 6/06)

Component calculations and simulation tools for FAN5234 or FAN5236 / AN-6002 - Fairchild Application Notes / (app note added 6/06)

Component Reliability - Zetec Semiconductors Applications Notes This note introduces basic reliability theory, failure rate analysis, and product qualification methods, and includes sample data and FITs values for a variety of test methods. (app note added 2/06)

Components Calculations and Simulation Tools for FAN6520A / AN-6009 - Fairchild Application Notes / (app note added 6/06)

Connection tester - (electronic circuit added 05/07)

Connection Tester - A low resistance ( 0.25 4 ohm) continuity tester for checking soldered joints and connections (added 09/05)

Conrad Electronics MM3610D multimeter cable pinout - (diagram added 05/07)

Constant Brightness LED Stroboscope: for Measuring the Speed of Small Motors - The rotary switch is available for $5.00USD as of 2003 from DigiKey under part number EG1951-ND or EG1952-ND. It is a real pain to operate this circuit without a proper switch. You can put multiple 4017 ring counters in series to reduce the duty cycle in order to obtain a more focussed strobe image but you will have to increase L or by using a regulator to power.... (added 2/05)

Constant Voltage Load Tests Battery Chargers - 04/11/96 EDN-Design Ideas: (design idea added 3/03)

Contactless Mains Voltage Indicator - (electronic circuit added 10/05)

Continuity Tester - This is another invaluable piece of test equipment for digital work. It has been designed by us to cater for a particular application….(electronic circuit added 05/06)

Continuity Tester (Andrew Morris) - This circuit senses only dead shorts on a populated board. It will not ring through or damage components. It shuts off when not in use. It was first published in Electronics magazine, June 21, 1979, page 145 Designed by Andrew R. Morris (added 09/05)

Continuity Tester (Tony van Roon) - Starting with a 9 volt supply, when the probes are shortcircuited there is a 8.2 volt drop across the zener diode Z1 leaving a maximum of 0.8 volt across R1. Application of Ohms' Law showse ....(circuit added 04/05/06)

Continuity Tester Latching - Awesome tester!at least in the designers opinion! (Tony van Roon's electronic design added 5/02)

Continuity Tester Smart - (Tony van Roon's electronic schematic / circuit added 4/02)

Continuity Tester, Low-Voltage - Several simple circuits were tried -a lamp, battery and probes still demanded the attention of the eyes; replacing the lamp with a buzzer was more successful but needed some three to four volts and gave no indication of a series semiconductor....(Tony van Roon's electronic design added 2/06)

Continuity tester-essential for digital projects - This is another invaluable piece of test equipment for digital work. It has been designed by us to cater for a particular application . . . servicing digital projects sent in for repair….(diagram added 05/07)

Convert your DMM to a pH meter - 10/17/02 EDN-Design Ideas: It's often necessary to know the acidity of a solution to control a process. Even inexpensive pH meters can be relatively costly, and many of the inexpensive models have no output that you can readily connect to a computer interface. A simple solution to this problem is to attach a pH probe to a high-impedance input of an op.....(design idea added 1/05)

Create your Own Meter - (electronic Circuit diagram added 03/03/03)

Creating a Reactive Energy Pulse Output Based on the ADE7753 - AN-758 Analog Devices Application Notes (app note added 6/06)

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Testers: #'s A-B C D E F-G H-K L M-O P Q-R S T U V-Z