Recent content by rueffy

Yes your calculating correctly, using my resistor/capacitor values it will come out at 75k. I'm not 100% certain why this is the case, but I think it has something to do with the op amps - I tried a range of different op amps using the same resistor/capacitor combinations and the frequency would...

That's a good point, thankfully my diode has a rotating lens for beam dispersion control, not sure how common that is? I've tried about 3 different diodes all up, one of them came separately from the lens, which was a real pain as it involved having to position the lens exactly the correct...

Thank you to all those that helped contribute to the development of my circuit (particularly Cyparagon). The project is now fully functional and I've made a video as part of my presentation to a class, the video shows the system in operation with a full description of signal flow etc...

Thank you to all those that helped contribute to the development of my circuit. The project is now fully functional and I've made a video as part of my presentation to a class, the video shows the system in operation with a full description of signal flow etc...

Thank you to all those that helped contribute to the development of my circuit. The project is now fully functional and I've made a video as part of my presentation to a class, the video shows the system in operation with a full description of signal flow etc...

Yes, my other laser had seen a little too much experimentation. I have a LASER diode now. More information available if needed. 10mW Laser Diode 10mW laser diode component, red in colour and supplied with 7mm dia collimating lens. SPECIFICATIONS Threshold current: 24mA Operating voltage: 2.4V...

Thank you for your help thus far, I appreciate your continuous help. Short removed, limited success, I had a very dull beam, wasn't bright enough to get the receiver up and going. I've sat down tonight and come up with an alternative circuit, does it look viable? My diodes requirements are...

So what your saying is I should have the LASER negative connected to the source/ground?

PWM generator is fine, tested it prior. You mentioned in your post You've got the Laser + and Laser - next to each other, I too noticed it was shorted, I took it your list of components was a series list, starting at top to bottom.

Oh I see, no you were clear, I just have a habit of getting excited and rushing things. So just to confirm here is the configuration you've suggested, Laser + and Laser - are next to each other, is that correct?

This is the current configuration, I've checked all my connections, done a little re-soldering and now I just have a constant high pitch wail masking the majority of the audio (the audio is there, it can be heard). It's as if I'm picking up unfiltered PWM now.

Bingo, you were spot on. I reversed my drain and source and threw in a 1k and grounded it, I've now got PWM on the LASER input, the LASER is a little bit dull, but it appears to have a sufficient response time and enough power to raise the receiver above the 'reception' threshold. The received...

I've got the thing powered now, no luck with operation however, using the circuit in my first post, I have a nice 0/9V PWM signal on the MOSFET gate, the drain of the MOSFET is showing a constant 8.26V however, shouldn't the drain voltage / the voltage across the 100ohm resistor R11 be similar...

I have some fairly conflicting information on that, not that I'm disagreeing you but a lengthy tutorial on LASER PWM Comms specifically said not to vary the voltage, extract at the bottom. Am I interpreting this incorrectly? Using laser pointers for voice communications

The system is battery operated, the LASER is 5mW, there is a .25W audio amp in the circuit.. Yes I guessing its classed as low power.