Pre paid electricity meters have a way of running out of credit when you least expect it, leaving you in the dark late on Sunday night!
Likewise, coastal town sewerage conservancy tanks get full and overflow unexpectedly with nasty results. Our dual monitor keeps an eye on both the tank level
and the electricity meter credits and conveniently sends you a SMS when you need to take action. They are also controllable remotely via SMS.
As an added bonus it can open your door remotely via a PIN encoded SMS to admit guests, and you can turn your geyser (HWC) on and off remotely as well.
Of course the unit can also monitor saved rainwater tanks.
Detailed features: Read the manual |
![]() |
These are HI FI quality 50W RMS Audio amps originally designed to be used in bridge mode to produce 100W for a guitar amplifier, but they can be used anywhere a robust clean amplifier is needed. | ![]() |
Over the years I have bought/built many Inductance meters, none of which gave me the accuracy I needed for inductances less than 1uH. This meter is based on the Carver design (See original article) which gives superb accuracy and repeatability but requires lots of fiddling and some tricky maths for each measurement. Adding an Arduino to idea with a built in frequency counter and some maths crunching, turns it into a very decent LC-meter. As a bonus it also measures capacitance. The design idea is to use an oscillator running at 1MHz with a calibrated fixed capacitor. When an inductor or capacitor is introduced into the tank circuit the oscillator shifts frequency. This shift is used to calculate the inductor added. |
![]() |
![]() |
The bat phone allows you to listen to bat sounds which are above our hearing range. It is tunable from 20kHz to 150kHz and is a full heterodyne type receiver. |
This unit has 2 divide by 10 outputs and a RF preamplifier. Arduino based frequency counters only work up to about 4MHz. Using this unit you can go up to 40 or 400MHz. |
![]() |
We used an Arduino to provide 12 different bubble pattern programs and lighting programs for this wall mounted or room divider bubble curtain.
The video clip only shows a small fraction of the variety of programs. The curtain is installed in the Visions Gallery in Hout Bay and the idea was conceived by Jacques meyer
(www.visionsgallery.co.za)
See the YouTube Demo here. |
These are PIC or Arduino based controllers to drive FastSPI LED strips, where each LED in the strip is uniquely addressable in terms of it's brightness and RGB levels.
Click on the picture for a YouTube demo. The possibilities are as limited as your imagination. As each 'pixel' is individually addressable, any kind of motion and direction can be achieved.
We design the hardware to specification as well as all custom software to achieve the effect you desire. See the YouTube FastSPI Demo here. |
This project was developed to meet the criteria for upgrading from a ZR to ZS call sign, ie a 1W CW only transmitter. It was designed to be as simple and with as few components as possible, and yet still actually function with reasonable performance. Its called the 1 hour TX because that's how long it takes to build the kit. Put another way, all that stands between a new radio ammeteur (ZR) and a ZS call sign is 1 hour of real amateur radio stuff. This is a low tech project suitable for novice constructors and can be made with a minimum of equipment. |
![]() Click here to go to the project page...... |
![]() Click here to go to the TID Amp |
This is a high quality, precision audio hi-fi amplifier designed to minimize THD. As most naive hi-fi buyers compare harmonic distortion specs between amplifiers and influence their choice on little else, manufacturers compete by using large amounts of negative feedback to reduce their total harmonic distortion (THD) to low levels, while, sacrificing transient response. The ear can not hear harmonic distortion below about 5%. Even excellent loudspeakers produce 1 to 5% THD at low frequencies! TID is seldom specified in commercial hi-fi amplifiers, as it is difficult to measure. Some designers now hold the view that in current amplifier designs, harmonic and inter modulation distortion levels are so low that transient effects are the main cause of audible differences between designs. |
For 30 years I have been designing and building custom HF and VHF band radio transceivers. These are mostly for the Amateur Radio bands and have been aimed at low power and light weight. |
![]() Click here to go to the Transceiver page...... |