Optical sensor

Help Please on this part .fits on a Motor drive circuit board Medela symphony breast pump. Its a type of optical sensor. Its 2 parts Top of the L shaped bracket has a sender unit white in color like flat LED that shines downward to a square shaped photo sensor. It counts pulses of light shining threw a gear. There is no markings on these parts but i will say kind of looks like these parts shown on ebay ?

ant info offered on ideas of where to find part numbers or parts would be great. Thank you MVC-003F MVC-007F MVC-002F

Hi ilovetoysto,

It’s going to be pretty hard to nail it down to an exact part. Nearly identical sensors have different output types, so there is no simple way to know which would be the most likely solution.

It looks like you believe the sensor has 3 pins. Usually that means that it has a power, ground, and output pin, and that it will be a logic output type rather than a transistor output type, which usually only has 2 pins.

Typically the center pin is the output. If that pin has a resistor connected between it and the power supply, then it is an “open-collector” type of output, but if the pin signal only goes to another chip on the board, it is probably a “push-pull” type of output.

Now, the part that is impossible to know is whether the output is inverting or not. This refers to whether the output goes high when it sees light or low. Depending on the particulars of the design, this may or may not matter.

Here are the detectors we stock which may work in your system:


Here are a few emitters to consider. They should work with any of the detectors linked to above.


Thank you very much for your info. The LTE-302 looks very much like the correct part that fits into the L bracket. Is it common for this item to get weak over time. The collector may be fine just week emitter ??

Also i did check the voltage to the emitter the other day it was 1.2 volts so The LTE-302 sounds correct??

Quite possible. If an emitter is driven pretty hard, it can weaken over time. That is probably the more likely part to fail, though no way to know for sure.

Thank you the LTE-302 very low dollar part and easy to change, I will order this part on thursday give it a try. Thanks so much for all your help David

One little problem i think the LTE 302 is to wide says 4.45 MM I did take out the emitter shows to be 3/16 wide so the 302 wont fit. is there another much like the 302 that is not so wide ??


Hi ilovetoysto,

It is actually a tad narrower than your part. 3/16" is equal to 4.76 mm, so it should be OK in that dimension.

ok Thank you

Thank you so much all your help. the part you picked (The sensor ) clearly is correct. The pump is working fine again. Thanks again David

One more question please. you clearly have found the correct part for the emitter Thanks… I have one more pump that still acts up. I suspect the director/collector That receives the signal from the emitter. I have few pictures but again no markings on the unit.I did look on the website to try few a parts that looks alike ??? PT5529B/L2-F ??




Hi ilovetoysto,

Again, very hard to say. The package shape of the PT5529B/L2-F does look right. That particular part is not in stock, but the PT5529B/L2/H2-F is in stock. They are physically and functionally, nearly identical.

This part would typically have pins 1 and 3 tied to ground and pin 2 would have a resistor connected between it and Vcc (your voltage supply) and pin 2 would also connect to the device which receives the on/off signal.

Thank you very much for your help.So by looking on the website there are 3 item numbers that look very much like the item in the picture. would you just order small number of the PT5529B/L2/H2-F and see if it works. if it does then order more ??

Hi ilovetoysto,

I think the PT5529B/L2/H2-F is the only one of those currently in stock, so that’s probably your only option at the moment. Decent chance it will work, but no way to say for certain.

ok thank you so much. do you think i can buy it in low numbers to try it ??

You can purchase any quantity you wish. There is a shipping charge, which varies by location in the world and method chosen, so keep that in mind, from a value standpoint. We do sell other items like batteries and such if you want to make it more worthwhile.

If in the US, here is a link to information on various shipping methods and rates.

Ok i just now placed order. Thanks so much. so smartest way is just take a working circuit board swap in that part see if it still works.That will be great if it works . I will have all major components for that circuit board. Thanks again David