12V Low Battery Relay – Monitor

I have been updating information on a low voltage detector for 12V battery monitoring. When the applied nominal 12V supply drops below the trip set-point, the relay changes state. This can be used to switch off equipment or trigger an alarm etc. when the battery voltages drops too low. To […]

low battery relay

A failed ESC

ESC selection, failure and reliability

Selecting a ESC for your RC model Always Over-spec the ESC to be safe, even with the “good” ones. I’d suggest 50% over, and the HK ESCs are OK. For a 40A rated motor, choose a 60A ESC. Always start with a power meter connected and increase the throttle while […]


Another failed Seagate hard drive

Another Failed hard drive Over the last several years I’ve lost three 500G and the latest a 1TB hard drives, all Seagate. All started making occasional clunking noises that turned into a regular clicking and no access. The 1TB drive failed within the warranty period. The NZ supplier had disappeared […]

Seagate 1TB 7200 - failed drive

stainless wire heating

Wire heating power supply – 25+Amps

This was a small one-off project due to the need to heat 120mm long pieces of 1.5mm stainless steel wire as part of an industrial process. It had to be quick, simple and safe. In total, about 7 hours work from initial evaluation to boxed and ready to connect to […]


PIC-micro Assembly code example

This is an PIC16F assembly code example. Created originally about 10 years ago. It includes chip configuration and UART RS232 support using buffers and interrupts. The original application was a controller that consisted of a PIC16F876 connected to a PC via RS-232 and to a PIC16F676 via a fast clk/dat/int […]

PIC assembly code

HDD power supply repair

External HDD power supply repair

Faulty HDD Power Supply This external hard drive power supply was unreliable suggesting a bad solder joint was the cause. It is rated to supply 12V DC at 2A and 5V DC at 2A. Inside Inside is a typical budget switch-mode power supply. The through-hole components make it appear quite […]


A simple RTL controler for RC models

I think I’m going to have to pull finger and look at building a simple RTL controller for RC model planes. This post is a series of notes just to put it all in one place and provide some food for thought. Comments or questions are welcome. So what is […]


RC transmitter module failure

Corona CT8J Module    I’m using a Turnigy 9X transmitter with ER9X firmware and a few different transmitter modules including this Corona DSSS 2.4G. I recently had a few control problems with the Corona DSSS system and finally noticed that tapping the module could make or break the RC link. […]