Kempton Park Amateur Radio Technical Society
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Digital Clock & Temperature meter for the Shack
I had the need for a Digital clock with Temperature indication for my shack and decided to rather build one than scan Amazon for
something suitable.  It was clear from the beginning that I would have to use one of the micro processors.  In my case, I prefer to use the
PIC Micro 16F886 which have all the hardware and registers to communicate on the I2C bus with the DS1307 Clock chip.
I used the DS18B20 chip to give me the current temperature.  This chip uses the 1-Wire bus to communicate with the 16F886.  This bus
control is done in software, unlike the I2C Bus which in this Micro Controller is controlled by internal hardware and firmware.
The temperature is updated about every five seconds while the clock is updated every second.  The minutes, hours, day of the week, date
of the month and year is set by four switches. 
The DS1307 has an input for a 3Volt battery to keep the clock going during periods of no power to the circuit. The chip has an onboard
oscillator controlled by an external 32.768 kHz crystal.
For more Information on the Digital Clock & Temperature meter, Please download the pdf document.
Download
For orders, Please contact: Trevor Reynolds (ZR6TW)
Email:  trevor.r1010 (at) gmail.com

NB! The Metal Enclosure Boxes is not included.
0-28 Vdc Power Supply
This is a high quality power supply with a continuously variable stabilised output adjustable at any value between 0 and 28VDC. The circuit also incorporates an electronic output current limiter that effectively controls the output current from a few milliamperes (2 mA) to the maximum output of three amperes that the circuit can deliver. This feature makes this power supply indispensable in the experimenter’s laboratory as it is possible to limit the current to the typical maximum that a circuit under test may require, and power it up then, without any fear that it may be damaged if something goes wrong. There is also a visual indication that the current limiter is in operation so that you can see at a glance that your circuit is exceeding or not its preset limits.
For more Information on the 0-28 Vdc Power Supply, Please download the pdf document.
Download
For orders, Please contact: Trevor Reynolds (ZR6TW)
Email:  trevor.r1010 (at) gmail.com

NB! The Metal Enclosure Boxes and Transformer are not included.