Introduction The problem was this...at Redeeming Grace Church we were meeting in a public school prior to moving in to our permanent facility. Each Sunday morning we would bring in three large percolating coffee pots to brew regular, decaf, and hot water for the mid-service break time. Each pot drew 9 amps. Because the average 120VAC power receptacle "outlet" in the USA is protected by a 20-amp breaker, thr ...

ave an old hard drive that no longer works? As long as it still spins up chances are you could build a clock out of your old hard drive! You will need some electronic knowledge, some common electronic components and a bit of patience. The clock that is produced isn’t exactly practical since most hard drives (especially older ones) are too loud for a clock that is to operate 24 hours a day. VIDEOS Watch a vi ...

Introduction I obtained an early vintage Radiodetection® RD400 "LLTS" Precision Line Trace unit for a very low price through eBay. The RD400 is the receiver portion of a transmitter/receiver pair that comprise an underground cable locator system. Because the matching transmitter was not available (hence the low price,) I had to design one that matched the two audio frequencies detected by the receiver. "LLT ...

An extremely simple and low cost Sine/Square wave generator based on the Analog Devices AD9835 Direct Digital Synthesis (DDS) Generator chip. The frequency can be set for any frequency from 1Hz to 10MHz in 1Hz resolution steps! All this with three push buttons and a novel "sliding window" LED display. The controller chip is a Microchip PIC16F628. There is no wiring, and the PCB fits into a standard UB3 Jiff ...

Introduction This program is a simple combination lock that I designed for an old Sentry® fire safe that was given to me without any lock electronics. I created a front panel with a keyboard and microprocessor with a six-digit combination sequence. Details The LED flashes to show it's alive after power is applied. The lock solenoid requires 6VDC at approxmately 2 amps. Given that a small 9V battery is used ...

Introduction This project is for the hobbiest who wants to build a measurement and display unit for an Awana Grand Prix® track (also known as a Pinewood Derby track.) The racetrack for which I designed this unit is a 4-car track. A car is approximately seven inches long, is released by a gate at the starting line, rolls down the ramp by gravity, and crosses the finish line in approximately five seconds. Thi ...

Introduction This program is an experimental timed-discharge adapter for a Vericom control panel used with an Orenco Systems AdvanTex® wastewater treatment system (sewage filtration system) marketed by Wastewater Technologies, Inc. Although the Vericom firmware is capable of modification to provide timed-discharge capability by a firmware download via telephone, this adapter was just an experiment to prove ...

An extremely simple and low cost Sine/Square wave generator based on the Analog Devices AD9835 Direct Digital Synthesis (DDS) Generator chip. The frequency can be set for any frequency from 1Hz to 10MHz in 1Hz resolution steps! All this with three push buttons and a novel "sliding window" LED display. The controller chip is a Microchip PIC16F628. There is no wiring, and the PCB fits into a standard UB3 Jiff ...

This simple project uses a Dallas DS1820 one wire temperature sensor and a pic 16f628 microprocessor. A simple temperature regulator where a LED symbolizes the Fan. Data derived from the DS18s20 is a 9bit centigrade temperature measurement. As mentioned the temperature sensor communicates over a one Wire bus that requires only one data line and ground for communication with a central microprocessor. The DS1 ...

It's 1970 and a 12 digit LED Display for pocket calculators has just been released. Nation Semiconductors are in the forefront of designing miniature displays for calculators and have a range from 2-digit to 16-digit displays. The actual 7-segment displays are so small it takes a bubble magnifier in front of the LEDs to see the digits. We have used one of these in this project. Fast forward to 2011. These d ...