SparkFun Forums

[Boy80]

Hi boys,
I've a device that works with a lithium battery (3.9V detected) and a usb connector for recharging.
So, if I remove the battery and connect 5V and gnd through usb, it's works?
I damage it? If so, how can I do this?

Thanks.

[DanV]

Why would you ask for help with a device and not tell what device?

[Boy80]

Sorry, it's a mini dv camera, that is:

http://www.ebay.com/itm/Mini-DV-Wireles ... Sw32lYnnhw

The ic p/n is H81544CG7V1 but not found datasheet.

Thanks

[DanV]

Sorry, I cannot get onto EBay while here at work - corporate blocks EBay.

I don't think looking at the IC requirements is relevant - your device should have circuitry to handle battery charging as well as regulating voltage for the device but I can't say for sure ...

[Boy80]

there are no other ic, only 25q40t for SD card..

[Boy80]

Photos:

[DanV]

The only thing I could find online by searching via GOOGLE "mini dv camera 5mp"
was "Charged by: USB port or 1x external AA battery"
so, I don't know the answer to your question ...

[Boy80]

Battery removed, nothing, no power on with usb.
So, can I connect 3.7V from a dc power supply to battery pins?

[jremington]

Try it, you have nothing to lose because the components on the PCB may have already been fried.

[brianuno]

I have one of these novelty cameras. I don't remember if I got it to work, but I was curious what it looked like inside. What is the round thing in the lower photo, upper right, bobbing on two wires, above the SD card? It looks easy to remove, but for what purpose?

[Valen]

The small cilinder on wires is likely a electret microphone. I could be mistaken but I see a "M" on the other side of the board where the wires attach. I mean, I see little point in a motor-buzzer as a feature, or that needing so many passive parts around it. It must be for filtering the audio or supplying phantom power to it.

https://en.wikipedia.org/wiki/Electret_microphone

[brianuno]

A microphone, of course. This camera probably doesn't have a working microphone, but it is needed for continuity. I understand these parts can work as either as a microphone or a buzzer, a Piezo element to be exact, right? I have a SparkFun experimenter kit which includes a buzzer tutorial, but an actual buzzer component wasn't included with the other accessories. No problem. Salvage one.

[Valen]

The exact makeup of that thing is all speculation. Electret is most likely because of it's size. Piezo buzzers or contact microphones are usually flat disks. You'd have to look for partnumber markings and look that up to be sure. And piezo's work quite differently compared to electrets. The former works by displacing charge, causing voltage changes when deformed. The latter needs a voltage applied which it will modulate as the membrane is deflected. As for dual purpose, I highly doubt that. Microphones which are supposed to be excited easily by air vibrations are lousy speakers or buzzers which are supposed to make the air move. It may give some signal, but you'd have to amplify the heck out of it to be usefull.

[brianuno]

I will get a new buzzer. The tutorial has it play a tune. New parts cost pennies. Not worth my time to figure out. I have another question about salvaged electronics. I will post it in the General Chit-Chat forum.

[Boy80]

I soldered an electrolytic capacitor (10uF) to battery pins and works with the usb 5V (without usb data wires connected).