Need to design an IR Receive amplification circuit for digital processing

[stj]

Re: Need to design an IR Receive amplification circuit for digital processing

I'm not sure how any of this information is relevant to my original question, which was... how do I design a circuit such that when a voltage hitting the base of a transistor is at 5V, the transistor is off, but when that voltage goes to 4 volts or lower, I need the transistor to be on as hard as it can be?

you need a schmitt-trigger like a 74hc14, not a transistor.

but that's not going to help because your reciever output is already digital - you need a better and more sensitive one.

[EasyGoing1]

Re: Need to design an IR Receive amplification circuit for digital processing

you need a schmitt-trigger like a 74hc14, not a transistor.

but that's not going to help because your receiver output is already digital - you need a better and more sensitive one.

I'm not convinced that it won't help, because when a weak signal reaches the receiver, it sends a higher voltage to the Arduino ... and as I stated when I started this post ... if that pin gets between 2.2 and 2.5 volts, it will waffle the interrupt trigger, so if I can set 4 volts as an absolute that will guarantee sinking that pin to ground, then I will have completely overridden the effects that a weak signal has on this ir sensor and I will have given the Arduino a solid 0 even if the IR receiver gets a weak signal ... (because a strong signal causes the IR receiver to go to about 1 volt while a weak signal can make it only drop to 2-ish volts) ... so then with this idea, all that signal needs to do is drop that voltage by only 1 volt and I'm in business ... make sense?

[budm]

Re: Need to design an IR Receive amplification circuit for digital processing

You still refuse to give us the spec of the IR receiver you are using and also the waveform, simple request.

[redwire]

Re: Need to design an IR Receive amplification circuit for digital processing

We don't know how OP is measuring the pulse voltages. With a multimeter it's averaged and doesn't tell you much.
OP is also thinking a weak signal means less signal swing which is not the case with modules because they have built-in amplifiers, AGC, clamps and a comparator to give the same output signal weak or strong IR signal.

A photo-transistor will give a weak or strong signal though, so this seems part of the confusion or maybe even what OP is using for a receiver. We will never know.

[budm]

Re: Need to design an IR Receive amplification circuit for digital processing

We don't know how OP is measuring the pulse voltages. With a multimeter it's averaged and doesn't tell you much.
OP is also thinking a weak signal means less signal swing which is not the case with modules because they have built-in amplifiers, AGC, clamps and a comparator to give the same output signal weak or strong IR signal.

A photo-transistor will give a weak or strong signal though, so this seems part of the confusion or maybe even what OP is using for a receiver. We will never know.

Yep, we will never know. OP asks questions but refuse to provide the info + lack of basic understanding of the electronics and devices.

[truclacicr]

Re: Need to design an IR Receive amplification circuit for digital processing

Use a single supply, rail to rail comparator, eg MAX941.

https://cdn.badcaps-static.com/pdfs/...acaf490fe5.pdf

Use a resistive potential divider for the 4V set point (see figure 6 on page 9).