2017-05-20_APeakInside.md

2017-05-20

Content

Counter going in:

• 1st board: counter: 6 wires going out of counter, 6 feeding in LM339, 6 wires going out. LM339 is Quad Differential Comparators

• 2nd board:

  • DM74S287AN: 1 green wire coming from ultrasound machine, 1 connected to LM339, 3 others from machine. Seems a schottky memory 256x4 1024-bit TTL PROM. The 4 pins on this side seem to go to Q0 to D3. Only Q3 is connected to green wire.
  • HEF4040BT: a 12-stage binary ripple counter. VDD from 3V to 5V. VDD is fed through the "salmon" wire. CP (Clock) is Wire4 (blue)

Guesses

• DM74S287AN stores the probe number / serial / ...
• The LM339 plays with the sensor.

Images

From the last image, data from the wires from the sensors

• Blue -> 5V
• White -> 2.2V
• Yellow -> 3.6V

Orange

20ms of period, that's 50Hz, that could be 50 imgs per sec, or since the periods seem divided in three, maybe that's a full turn of the head, so 3 images.

Green

The others are 28 to 30kHz, 30us/period. That's a period 1/600 of the period above. That can therefore be 600 lines / image, or rather

Violet

Sensors

Pins

• 9 et 10: motor (which one is the GND?)

• 16 and 2: what are those?

• 18 + 18

• 17 GND

Next steps

1. Power the motor
2. Connect intelligence on 16 and 18
3. Try powers around 17 and around

Possible encoders

PINS