Elegant PCB 24h Wall Clock DIY KIT
with an LED RF detector
This Radio-Room Wall-Clock project represents my 2nd attempt to mix something "artistic" with Engineering. The first attempt was made with the Elegant PCB Ruler for which I am receiving many nice comments, thanks to all my friends who have appreciated the effort.
The story begins with the commercially available clocks for the radio-shack. I have bought a couple of them in the past for my own shack and I didn't like any of them really. The design was not attractive, they look "cheap" and they are cheap while sell expensive and as I am getting older in age that ticking noise gets annoying. So I have arranged with a factory in China to make it as quiet as possible with the ticking movements on a special order and after I have came up with a dial design that I finally like it is time now to demonstrate the result.
The clock's face plate has a small passive circuit printed that uses a dipole antenna connected to a double Schottky diode chip which is used to rectify the incoming RF energy to finally power a small LED. Similar to an "ON AIR" sign as seen in broadcasting stations, hopefully it will light up with every transmission getting out from the shack. The small circuit takes the place of the commonly used space for a clock's brand name and since this project is not commercial, that exactly thing makes this clock unique, at least to the non clock expert. The 2 mm thick FR-4 PCB used with its 3-oz copper thickness and adding the gold-plating (ENIG) and the silkscreening makes a really expensive clock dial, but it really shows elegant, unique and amazing and worths it's cost.
Attention: The RF detector is not so sensitive, a handheld V/UHF xcvr needs to be placed close for the LED to light.
Face Dial:
Circular Printed Circuit Board, 216 mm diameter ENIG (Gold plated) , 3-oz (102 microns) copper thickness, plus nickel plating plus gold plating, 2 mm thick FR-4 material
Hands Dimensions:
Minute Hand: 89.8mm
Hour Hand: 61.4 mm
Movement Specifications
Crystal Oscillator: 32.768 KHZ
Time Keeping: +/- 1 sec/day @ 1.5V, 24C
Operating Voltage: 1.25 to 1.7V DC
Operating Temperature: -10 to 50 C
Torque: Second shaft: > 1.4 gf . cm (1.5 VDC)
Torque: Minute hand: > 30 gf . cm (1.5 VDC)
Driving System: Self-start ticking motor drive
Circuit output frequency: 8 HZ
Rated Voltage: 1.5 V
Battery size: AA (IEC R6) 1 piece
Battery life: approx 9 months
Average current consumption: <180 uA @ 1.5 V
Allowed Hand Length:
Second: 100 mm
Minute: 130 mm
Allowed Hand Weight:
Second: 1g
Minute: 3g
Allowed hand unbalance:
Second: 0.1gf.cm
Minute: 6 gf.cm
The components are factory soldered on the PCB. The buyer needs to assemble the clock movement and hands to the clock PCB dial. All parts supplied.
