13-02-2014, 01:40 AM
This challenge of a project is nearing its mechanical phase and it is time to come to Golborne where the best metalworking skills are.
The final electrical challenge is the lens telemetry PCB.
Would you tackle it if it was on your bench?
It is a little bit less daunting than it looks as there are three pairs of driver transistors on the board and the lens has three motors.
There is a spare pair of pins on the big chip that could drive a fourth motor if transistors are fitted and if these were fitted the back focus preset has a fourth motor that used to be the main focus for a fixed focus lens.
There is also an auto iris driver too.
The bit I will not be using is the RF over power signal. This uses a ZN414 TRF on a 3 pin chip device. I will generate the signal in the wired remote and feed it direct via a coax so the ZN414 will not be used. I have a full data sheet for the chips and the board and the remote will be a stable oscillator with a chain of resistors and push buttons.
The entire board requires just HT and two reference pulse wires from the sync pulse generator in the camera that are on a pair of solder pads.
The whole thing started with a box of bits.
The test set has a bad earth on the line scan coil wiring so there is a bit od ringing on the left side of the picture.
The final electrical challenge is the lens telemetry PCB.
Would you tackle it if it was on your bench?
It is a little bit less daunting than it looks as there are three pairs of driver transistors on the board and the lens has three motors.
There is a spare pair of pins on the big chip that could drive a fourth motor if transistors are fitted and if these were fitted the back focus preset has a fourth motor that used to be the main focus for a fixed focus lens.
There is also an auto iris driver too.
The bit I will not be using is the RF over power signal. This uses a ZN414 TRF on a 3 pin chip device. I will generate the signal in the wired remote and feed it direct via a coax so the ZN414 will not be used. I have a full data sheet for the chips and the board and the remote will be a stable oscillator with a chain of resistors and push buttons.
The entire board requires just HT and two reference pulse wires from the sync pulse generator in the camera that are on a pair of solder pads.
The whole thing started with a box of bits.
The test set has a bad earth on the line scan coil wiring so there is a bit od ringing on the left side of the picture.
