Hobby Projects - Insulation tester, LED Circuits, Meters.

Friday, March 11, 2016

Electrician Tool – Continuity Tester

I had gone to buy some long wires at a electrician shop, when a terminal box had to be tested, he used a continuity tester.

Continuity Tester
When i used to buy electrical parts in the past, they used a tester box, made of wood. This had a bulb and a tubelight starter and two long wires (230v AC). The Continuity tester would light up a 40w lamp. Now he had a LED based one, so i got one for myself.

All it had, was two small cells in a plastic box with a LED, i was just flashing the LED as it looked nice thru the transparent box, it failed. The LED had burnt, the battery used. This product was not for monkeying around.

Now i performed a tiny design upgrade, I used a extra-bright 3mm Red LED with a 47 ohm resistor. Now it is robust, at least for continuity. The battery life can be good only if you make quick checks.

Improvements -

More protection may be needed to avoid damage to LED when this tester is applied across a battery by mistake. LED can flash to save battery power, one SMD - LM339 can be used for flashing and a more efficient short-leakage detector. A small oscillator with a neon may be more efficient and bright. This can also double up as a hidden Live wire or Mains AC detector.

Continuity Tester Circuit

A single chip metal detector with a range of a few inches. This is useful for detecting nails or screws in walls and floors, or for locating buried mains cable.

Tuesday, March 08, 2016

CodeShield for Arduino - Diyode

The Diyode Codeshield is an arduino shield (add-on board) designed to make the process of learning (and, more importantly, teaching) arduino much more engaging and accessible.

CodeShield for Arduino - Diyode

The Diyode CodeShield was developed to make the process of learning code, specifically arduino code, much more intuitive and engaging. The idea is simple: put all the common inputs and outputs on a single board......

CodeShield for Arduino - Diyode

The Diyode Code Shield has:

Inputs: switch, button, potentiometer, rotary encoder, thermistor, photocell, and hall effect sensor.

Outputs: Piezo buzzer, servo motor, RGB LED, LED, and a relay with screw terminals.

"The Codeshield is a product of the Diyode Community Workshop. Diyode is a non-profit organization in Guelph, Ontario. Our mandate is to support, evangelize and teach DIY, focusing on woodworking, metal working and electronics."

Thursday, March 03, 2016

Switching regulator for 3.3V

Circuits with 3.3 volts: For small currents, a voltage regulator is sufficient. Greater efficiency can be achieved with a step-down switching regulator. This circuit proposal is loaded with good one ampere.

Switching regulator for 3.3V

"The switching regulator used works with an oscillator frequency of 52 kHz, the efficiency is mentioned in the data sheet with 80%. The manufacturer guarantees the accuracy of the output voltage of 3% and lists other advantages as a protection against over-temperature and current limiting on. The switching regulator requires a storage inductor (coil) high quality."