Serial Voltmeter using the PIC16C71

Monday, May 5th, 2008


Building a serial voltage meter to measure from 0 to 5 volts DC is actually pretty easy. Using MeLabs PicBasic, and Microsoft’s Visual Basic Version 5 Pro. You need Visual Basic Pro version because you will have to use Basic’s MSComm control. This control is not available in the Visual Basic 5 “Learning” Edition. The [...]

Voltage Level Indicator

Wednesday, March 26th, 2008


This circuit is derived from a Siemens Application Note 1974. This circuit uses common components of today. The circuit is here as it is of high educational value. I have not tested it. You can ’simulate and test’ or ‘wire it up and try’ and let me know how it worked. The Circuit is also [...]

High Voltage Protector for Meters by CA3130

Wednesday, March 12th, 2008


Normally, in a digital voltmeter, high input impedance of the preamplifier stage is protected against very high voltages by two diodes. One of them is connected to the positive terminal and the other one is connected to the negative terminal of the power supply. Practically this kind of protection is very sufficient. But the diodes [...]