## Ultrafire XML-T6 LED torch – a fix for the dysfunctional mode memory ‘feature’ #2

On review of the Ultrafire XML-T6 torch, I found the mode switching / mode memory so dysfunctional that it rendered the torch useless in my evaluation.

At Ultrafire XML-T6 LED torch – a fix for the dysfunctional mode memory ‘feature’ I gave a fix for that revision of the electronics, and updated it with description of a later fixed production model.

Years later, I bought two more of these due to switch failures on the originals… and guess what, the flash on power on returns.

Let’s pull them apart.

They have a new revision / version of the LED driver PCB, and it has provision for a resistor in parallel with the capacitor, but the resistor pads are not populated.

Above, the LED driver board with a 100k resistor added, it is the far component. This was an 0805 part that was on hand, but ideally should be a 0603. Continue reading Ultrafire XML-T6 LED torch – a fix for the dysfunctional mode memory ‘feature’ #2

## A handy 230VAC 15A inline power meter based on an inexpensive module from eBay

This article describes a simple and inexpensive inline power meter for use as a test instrument.

## CNC routing

The box cutouts were done on a CNC router, but they could be done with hand tools.

Above, calcs of feeds and speeds for the CNC router. The box is actually ABS, but cutting speed for Polycarbonate is the same.

Above is the tool path for one side of the box. The cutouts suit the 7P-2 strain reliefs. The gcode is generated from a custom Python file using a custom library of common shapes that I use. Continue reading A handy 230VAC 15A inline power meter based on an inexpensive module from eBay

## RK2672AM – calibration

The RK2672AM is a Chinese high voltage test set. This article describes a process for calibration of the device.

This process should not be attempted unless you have the requisite competencies, experience, tools and test equipment. There are dangerous voltages involved, so assess the hazards, plan your work, don’t attempt it if fatigued or alcohol enhanced.

Above is the front panel of the RK2672AM. Continue reading RK2672AM – calibration

## A handy 230VAC 10A inline power meter based on an inexpensive module from eBay

This article describes a simple and inexpensive inline power meter for use as a test instrument.

## CNC routing

The box cutouts were done on a CNC router, but they could be done with hand tools.

Above, calcs of feeds and speeds for the CNC router. The box is actually ABS, but cutting speed for Polycarbonate is the same.

Above is the tool path for one side of the box. The cutouts suit the 7P-2 strain reliefs. The gcode is generated from a custom Python file using a custom library of common shapes that I use. Continue reading A handy 230VAC 10A inline power meter based on an inexpensive module from eBay

## LED plate analysis – 24W round plate with driver

This article reviews a 24W LED plate and driver commonly sold on eBay and Aliexpress for around \$12.

Above is the 24W LED plate from the sellers pics. The plate has 48 0.5W 5730 LEDs in a 24×2 configuration. If we allow that the 24W rating is total input power, driver loss is typically around 2W so the LEDs themselves will draw 22W. We expect that the voltage at 22W will be around 80-85V, and will require ~275mA current. It is shown here with a 220mA LED driver or 80% of what is required for 22W. Continue reading LED plate analysis – 24W round plate with driver