Category: Hacks

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LED Lighting Part 1

Here I will document progress in replacing standard halogen MR10 lights with LEDs.

3x1W LED
3x1W LED

These units are from TruOpto, available through Rapid Electronics in the UK. They are 3W total, from 3x 1W emitters on an aluminium back plate.

LED Test Rig
LED Test Rig

Here is the LED attached to a heatsink for testing purposes – these units dissipate nearly 2W in heat at full output.

As the lights are to be run from a 12v battery bank, for simplicity a master regulator is required to provide a stable 11.4v rail for LED supply.

Regulator Module
Regulator Module

I have used a Texas Instruments part – PTN78020WAH. This is a 6A capable adjustable regulator module.

The LED lights are to be fully dimmable – the low voltage PWM dimmers are in progress of being built.

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Camcorder CRT Viewfinder

CRT Assembly
CRT Assembly

Here are the viewfinder electronics from a 1984 Hitachi VHS Movie VM-1200E Camcorder. These small CRT based displays accept composite video as input, plus 5-12v DC for power.

Screen
Screen

Here is the front face of the CRT, diameter is 0.5″.

Power Board
Power Board

Closeup view of the PCB, there are several adjustments & a pair of connectors. Socket in the upper left corner is the power/video input. Pinout is as follows:

  1. Brown – GND
  2. Red – Video Input
  3. Orange – +12v DC
  4. Yellow – Record LED
The potentiometers on the PCB from left:
  1. H. ADJ
  2. V. ADJ
  3. BRIGHT
  4. FOCUS
PCB Part Number reads: EM6-PCB
This unit utilises the BA7125L deflection IC.
Solderside
Solderside
Reverse side of the PCB, very few SMT components on this board.
Tube Assembly
Tube Assembly
Here is an overall view of the CRT assembly with scan coils. Tube model is NEC C1M52P45.
Electron Gun
Electron Gun

Closeup view of the CRT neck, showing the electron gun assembly.

 

CCTV Camera
CCTV Camera

The old CCTV camera used to feed a composite signal to the CRT board. Sanyo VCC-ZM300P.

CCTV Camera Connections
CCTV Camera Connections

Connections at the back of the camera. Red & Black pair of wires lead to 12v power supply, Green & Black pair lead to the CRT board’s power pins. Seperate green wire is pushed into the BNC video connector for the video feed. video ground is provided by the PSU’s ground connection.

Connections
Connections

Finally the connections at the CRT drive board, left to right, +12v, Video, GND.

Screen Operation
Screen Operation

Display taking video signal from the CCTV camera.