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Philips LED PAR38 Lamp Teardown

Philips PAR38
Philips PAR38

These large LED Philips PAR38 lamps were recently on clearance sale in my local T.N. Robinsons electrical contractors for about £3, so I decided to grab one in the hopes I might be able to hack it into a low-voltage LED lamp. These are full-size PAR38 format, with most of the bulk being the large aluminium heatsink on the front. The back section with the power supply module is secured with silicone, so some unreasonable force was required to liberate the two pieces.

Specification
Specification

These lamps are rated at 18W in operation, and are surprisingly bright for this power level.

Lens
Lens

The front has the moulded multi-lens over the LEDs, to spread the light a bit further than the bare dies.

LED Array
LED Array

The LED array is two series strings of 4 LEDs, for ~24v forward voltage. Unusual for a high power LED array, this PCB isn’t aluminium cored, but 0.8mm FR4. Heat is transferred to the copper plane on the backside by the dozens of vias around the Luxeon Rebel LEDs. There is a thermal pad under the PCB for improved heat transfer to the machined surface of the heatsink.

Control PCB Top
Control PCB Top

The power supply & control PCB is pretty well made, it’s an isolated converter, so no nasty mains on the LED connections.

Control PCB Bottom
Control PCB Bottom
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Sony Watchman FD-20 Composite Video Hack

VIF IC Pads
VIF IC Pads

Hacking the Sony FD-20 to accept a composite input is easy – the tuner receives the RF transmission, produces an IF, this is then fed into IC201, a Mitsubishi M51364P Video IF Processor. The VIF IC then separates out the composite video signal, which is output on Pin 13 (in photo above, left side, 3rd pin from the top). The audio is separated out & sent via Pin 11 to the Audio IF processor.

In the above photo, the VIF IC has been removed from the board with hot air, as it was interfering with the signal if left in place. The RF tuner was also desoldered & removed. Unfortunately I managed to mangle a pad, which is the ground pin for the VIF IC. This isn’t much of an issue though, as an identical signal ground is available, just to the left of the IC.

Audio Input
Audio Input

The audio can be tapped into in a similar way, the circled pad in the centre of the photo marked SIF is the place, this is the output of the Audio IF processor to the audio amplifier. The Audio IF processor didn’t interfere with the injected signal, so it was left in place.

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Camping Gear – Optimus Nova Multifuel Stove

Stove
Stove

For as long as I can remember I’ve been using Trangia-type alcohol fuelled stoves when I go camping, even though these have served my needs well they’re very limited & tend to waste fuel. I did some looking around for Paraffin/Kerosene fuelled stoves instead, as I already have this fuel on site.
I found very good reviews on the Optimus Nova above, so I decided to go for this one.

This stove can run on many different fuel types, “white gas” (petrol without any vehicle additives) Diesel, Kerosene & Jet A.

Burner
Burner

Here’s the “hot end” of the device, the burner itself. This is made in two cast Brass sections, that are brazed together. The fuel jet can be just seen in the centre of the casting.

Fuel Pump
Fuel Pump

The fuel bottle is pressurised with a pump very similar to the ones used on Paraffin pressure lamps, so I’m used to this kind of setup. The fuel dip tube has a filter on the end to stop any munge gumming up the valves or the burner jet.

Pre-Heating
Pre-Heating

As with all liquid-fuelled vapour burners, it has to be preheated. There’s a fibreglass pad in the bottom of the burner for this, and can be soaked with any fuel of choice. The manual states to preheat with the fuel in the bottle, but as I’m using Paraffin, this would be very smoky indeed, so here it’s being preheated with a bit of Isopropanol.
The fuel bottle can be seen in the background as well, connected to the burner with a flexible hose. The main burner control valve is attached to the green handle bottom centre.

Simmer
Simmer

Once the preheating flame has burned down, the fuel valve can be opened, here’s the stove burning Paraffin on very low simmer. (An advantage over the older alcohol burners I’m used to – adjustable heat!)

Full Power!
Full Power!

Opening the control valve a couple of turns gives flamethrower mode. At full power, the burner is a little loud, but no louder than my usual Paraffin pressure lamps.

Flame Pattern
Flame Pattern

With a pan of water on the stove, the flame covers the entire base of the pan. Good for heat transfer. This stove was able to boil 1L of water from cold in 5 minutes. A little longer than the manual states, but that’s still much quicker than I’m used to!

Fuel Jet
Fuel Jet

The top of the burner opens for cleaning, here’s a look at the jet in the centre of the burner. The preheating pad can be seen below the brass casting.