Now, just to be a good sport, Ialso opened up my flash and got a nice picture of the chip for you:
I dont know how much can be made out, but the lettering on the chip is:
The datasheet for TI’s line of AC14 chips can be found here:
I even whipped out the digital calipurs to be 100% certain which of the packages was being used on the chip, and its the plastic small outline package on page 15 of the datasheet, or at least so the 8.76mm length of the package tells me.
I believe that is SSOP, which makes the digkey part number: 296-4299-1-ND
Hmm, not so much. Its much simpler than that. Each direction has a transmitter IR LED, and a two prong IR phototransistor (or is it a photodiode? I dont recall, but it acts the same: the two prongs of the sensor allow current to pass if its getting light.)
The leg connected to one of the input gates on that chip is also tied low with a pull down resistor (before you ask, its a 4.7k ohm resistor on the original and the other leg is connected directly to power.
If there is no light on the sensor, then current cant flow, and the voltage on the input of the gate remains low. If there is light, then the current can flow, and the voltage on the input put increases.
The physical placement of the sensors is so that the actuator, in neutral, blocks all four light source. Moving a stick one direction un-breaks the light on the opposite side.
The chip has two main properties:
- It inverts the high or low coming from the input.
- It uses a ‘shmitt trigger’. This helps protect against random fluctuations; the gate won’t go low until its below a very low amount, and wont go high until its above a very high amount. If the voltage from the input was wishy washy and around the middle, the output would seem random.
So, what else ya wanna know about the flash? :lol: