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building usb-remote-cable

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Re: building usb-remote-cable
« Reply #410 on: 01 / February / 2012, 11:06:28 »
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Sounds like you've got a normally-closed switch. You need a normally-open one.

How do i do that?

Re: building usb-remote-cable
« Reply #411 on: 01 / February / 2012, 11:23:34 »
There are two kinds of switch. One of them is all the time conductive unless you press it. And the other is always not conductive unless you press it (then it becomes conductive). You got wrong one (the first type) and need to get (buy?) the other type.

It would be possible to build cirquit that inverts this behavior, but this is not the best idea I guess.
if (2*b || !2*b) {
    cout<<question
}

Compile error: poor Yorick

Re: building usb-remote-cable
« Reply #412 on: 01 / February / 2012, 11:24:58 »
Ok thanks for that, will have to wait till tomorrow when the market opens :(

Thanks for the speedy reply

Re: building usb-remote-cable
« Reply #413 on: 01 / February / 2012, 12:15:30 »
ryandigweed,

You should get a 'momentary' switch ... normally 'off', current flows only as long as you press, so a quick press/release triggers the camera. (Just like operating the shutter button.)


Re: building usb-remote-cable
« Reply #414 on: 01 / February / 2012, 12:32:03 »
ryandigweed,

You should get a 'momentary' switch ... normally 'off', current flows only as long as you press, so a quick press/release triggers the camera. (Just like operating the shutter button.)

Thanks for pointing that out bro. I thought al momentary switches were same. I went to the shop and asked for a momentary switch. I hadn't a clue there were normall "off " or normally "on" switches. :(

Will go tomorrow to the shop and get another. Just went to the market, and everything was shut :(

Re: building usb-remote-cable
« Reply #415 on: 01 / February / 2012, 13:12:38 »
Have a look here: http://www.kpsec.freeuk.com/components/switch.htm for a very clear description of switch types. ("(ON)-OFF ... push-to-make". That's the one you need.)





Re: building usb-remote-cable
« Reply #416 on: 01 / February / 2012, 13:42:44 »
Have a look here: http://www.kpsec.freeuk.com/components/switch.htm for a very clear description of switch types. ("(ON)-OFF ... push-to-make". That's the one you need.)

Thanks for posting that. Very Informative . Not really a electrical person. But the switch i got seems similar to
which is listed as a push-to-make switch. Nevertheless, i will go tomorrow and pick up a bunch of more switches. :)

Re: building usb-remote-cable
« Reply #417 on: 01 / February / 2012, 17:05:38 »
I believe that the illustrations are incorrectly placed; "(ON)-OFF" is usually black, red indicating a hot (live) situation. (The diagrams are correct.)



Re: building usb-remote-cable
« Reply #418 on: 01 / February / 2012, 17:45:07 »
Yeah, the same symbol as used in the schematic


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Guys i got this working.!, it's great. Just can't get used to the focus and exposure lock. Any more mods? :D


:D

It's exciting
« Last Edit: 02 / February / 2012, 14:36:39 by ryandigweed »

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Offline ahull

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Re: building usb-remote-cable
« Reply #419 on: 28 / March / 2012, 09:07:57 »
Just thought it worth fleshing out the details on the Lithium battery third terminal.

If you have the charger that came with your Canon camera, you will note that it also has three terminals, and the middle terminal is probably marked with a T, this either stands for Temperature or Thermistor depending on who you ask, but either way it is the temperature sensor. In a typical Canon branded battery, there is a thermistor (a temperature controlled resistor) connected between the T pin and ground, (I just measured the one in my NB-4L and it is about 10K Ohms at room temp.)

The Canon charger therefore uses the temp sensor to shut down the charger if the thermistor gets too hot.

In my cheap no name charger, this pin is not connected, I took it apart to be sure :~) so I run a greater risk of uncontrolled thermal runaway if I use the cheap no name charger. I was fairly sure would be the case, and I alway leave it sitting in the fire hearth when charging anyway, It is a useful little charger as it will charge a variety of different shaped cells. This flexibility is provided at the expense of two other properties.

First it charges much more slowly.

Secondly it is less safe. If the battery being charged fails and then starts to overheat, it will continue to charge, however since the charge current is very low and the batteries in question are relatively inexpensive, and any resulting fire would be in my fire hearth I am not concerned.

It is worth bearing this in mind however if you are charging Lithium batteries with a cheap charger, or ones where you are uncertain about their history or condition.

Most lithium batteries do contain some internal protective circuitry, but again this depends on the supplier and no name brands may save money by leaving this out.  High capacity cells and those used in certain situations (for example laptop batteries) are safer than others.

Lots of info on battery charging can be found in the usual places, for example http://en.wikipedia.org/wiki/Battery_charger

Do bear in mind however that although LiPo cells and batteries are not as "safe" as alkaline, even alkaline ones can catch fire and explode if shorted abused or used incorrectly (for exampe by attempting to charge them in a charger not designed for the purpose, and yes there are chargers out there that will recharge "disposable" alkaline batteries). Use common sense when dealing with any cell or battery  and you should be fine.
« Last Edit: 03 / April / 2012, 11:14:30 by ahull »

 

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