How can I make a simple contraption that consists of a switch that when pressed would delay for 41 milliseconds then output 5V DC current for 5 milliseconds? Is that something I could make with simple capacitors/resistors/transistors type of stuff?
Yes you could do it with a couple 555's or a logic gate. Someone for sure will ask how much current the circuit needs to supply, if it's more than a few milliamps you will need a transistor on the output. It also matters how precise the time delays need to be.
Thanks for the reply. The time delays don't need to be 41 milliseconds exactly but it needs to be consistent. How would I go about figuring out what parts to get and what specs should I look for? Is this something someone could sketch up really quickly?
I think this circuit might work; I simulated it (in LTspice), and it generates a ~1mS pulse, about 5 volts, about 12mS after power-on. You could probably tweak it to get closer to your specified timings.
**broken link removed**
So can anyone here tell us how to improve this? It doesn't exactly produce a square wave. What's the easiest way to square up the output? make sure the transistor is driven into saturation? (LTspice file attached below.)
Well, that aside, am I on the right track here? Can anyone come up with a simpler solution? (For my money, I'd like to see something without an IC like a 555. This is such a simple function that it seems to only need BJTs and such.)
Well, that aside, am I on the right track here? Can anyone come up with a simpler solution? (For my money, I'd like to see something without an IC like a 555. This is such a simple function that it seems to only need BJTs and such.)
So you'd, what, make Q1 an emitter follower and Q2 a common-emitter stage?
By the way, here's the trace I get from this circuit (somewhat modified, new LTspice file attached). Not too bad. A little wider than 1mS, but should be fine to trigger a camera with, I'd think.
I may be way off base with this, and if yes, I am sorry for questioning. I have a few DSLR cameras a Canon EOS 10D and a 7D. Both of these cameras as well as many other DSLR cameras I have worked with involve using a logic low signal for external or remote shutter release. The shutter release on my own cameras has a 3 pin connector. Two of the 3 pins are held at a logic high of 3.3 volts. They are held high through an internal pull up resistor. Placing either pin to logic low will fire a function. One pin is the AF (if used) and the other is shutter release. I just want you to be sure that an external positive pulse of 5 volts is what you want.