Hobby Projects - Insulation tester, LED Circuits, Meters.

Wednesday, November 20, 2013

The Mini Metrology Lab - Conrad Hoffman

This is a Article by Conrad Hoffman in "Electronics Now, April 1996".He has an intriguing collection of electronics and Mechanical DIY Tips and Ideas in his site.

The Mini Metrology Lab - Conrad Hoffman

The Mini Metrology Lab - Conrad Hoffman

His "Electronic Mess" section has many pages on repairing and restoring old instruments and equipment.

An Excerpt from his pages is a Reading Pleasure due to his rich experience and enticing language. 

Troubleshooting Audio Electronics
I ain't gonna lie. You won't be a master troubleshooter after reading a couple pages here. Hopefully, what I can do is give you the ability to form a logical plan of attack.

Troubleshooting is done mostly with the mind, not with the soldering iron. We all have problems that get the better of us, at least for a while, but approaching the situation as an interesting puzzle, rather than an unpleasant task to be suffered through, will make the work go quickly.

 Success will come from a 3-prong approach, a combination of understanding the circuit, having the means to test it and being in the right frame of mind to correctly interpret the test data. Never underestimate that third component.
He also has a Design and Testing Services called  Deep Run Design.

Sunday, November 17, 2013

Simple Water operated relay

This was done in my early days, i have upgraded it, it ought to work, reduce the number of transistors to make it less sensitive, also a lower value in place of 10M will reduce its sensitivity, use clamping diodes to protect.

BD139 is used to drive the relay as it has good Ic. So you can even use a low ohm relay. If a Relay resistance is high its quality is higher, its power consumption is less and it needs thinner wire SWG-AWG. T2 and T3 form a darlington pair which drives T1. LED1 shows that the water level has reached the top of tank and also that the Relay is energised. D1 a freewheeling diode. R3 10M ensures that the high gain input does not float, yet the low leakage current thru the water is not drawn away by the 10M. R2 limits base current in case water is saline.
Simple Water operated relay

See more at Circuits with Discrete devices

Wednesday, November 13, 2013

Raspberry Pi BitScope

A fully integrated Test bench based on Virtual Instruments - mixed signal oscilloscope, logic analyzer, spectrum analyzer and waveform generator using BitScope connected via USB or Ethernet to the now very popular Raspberry Pi.

Raspberry Pi BitScope

Regardless of which BitScope you choose, the new BitScope Library is also available making it easy to create your own embedded test, measurement or data acquisition applications using BitScope and Raspberry Pi. Program in C/C++, Python or Pascal using an easy to use programming API.

 Raspberry Pi BitScope

BitScope Model 10 - World's Smallest Mixed Signal PC Based USB Oscilloscope!

BitScope Pocket Analyzer. It's a problem solver that fits in the palm of your hand. Perfect for designing, prototyping and debugging!

It has 100 MHz bandwidth, up to 40 MSps logic, simultaneous waveform and clock generation and offers serial control of connected devices.  It's the ideal tool for prototyping analog electronics projects, digital and logic circuits or Arduino, Raspberry Pi and other microcontroller based systems with busses, sensors, servos and I/O.