Comments on: Serial port power booster http://hackaday.com/2007/05/19/serial-port-power-booster/ Fresh hacks every day Fri, 10 Feb 2012 18:02:36 +0000 hourly 1 http://wordpress.com/ By: Ash http://hackaday.com/2007/05/19/serial-port-power-booster/comment-page-1/#comment-26370 Mon, 21 May 2007 19:28:59 +0000 http://hackaday.iheartcashews.com:8181/2007/05/19/serial-port-power-booster/#comment-26370 Double plus good, this!

Now all we need is a current limited/fused molex connector for the rear-of-case and we can feed all our amp’ed gadgets. I’ve been toying around with the idea to get rid of those USB power overcurrent/spike issues. Of course someone should make a laptop release as well for the mobile toolkits.

]]> By: threepointone http://hackaday.com/2007/05/19/serial-port-power-booster/comment-page-1/#comment-26369 Mon, 21 May 2007 00:32:45 +0000 http://hackaday.iheartcashews.com:8181/2007/05/19/serial-port-power-booster/#comment-26369 I agree, there’s really not much of a reason to use the max205/203 here. The only reason for Maxim integrating the caps is more to reduce the board space used, and I don’t see this power booster as having portable requirements.

I think calling this a “power booster” is a bit of a misnomer. As I understand, the problem with using portable programmers is not so much the lack of power but the lack of voltage–you need to boost those roughly-ttl level signals from the usb-rs232 adapters to rs232 levels.

I’ve made one of these before with the max232 chip, and the biggest problem I have with them is that you still need an external +5V power source. I think a really great project would be one which draws power off one of the unused RS-232 lines and trickle charges a supercap (you could try a used line, but then you’d have to do something about the ~1F of capacitance slowing down the signals. . .) You might need a boost regulator to charge at ~5.5V and then use a LDO again for the MAX232 chip. I haven’t done the calculations, but I’m pretty sure that a programmer that uses about 20mA + MAX232 (uses

]]> By: alex mccown http://hackaday.com/2007/05/19/serial-port-power-booster/comment-page-1/#comment-26368 Sun, 20 May 2007 23:44:25 +0000 http://hackaday.iheartcashews.com:8181/2007/05/19/serial-port-power-booster/#comment-26368 my “super multi programmer” KILLS my *new* laptops battery i also am in the middle of makeing an extended bat but this is good and i have like 100 max 232s and 1uf caps so im coverd with that

]]> By: Spaceball1 http://hackaday.com/2007/05/19/serial-port-power-booster/comment-page-1/#comment-26367 Sun, 20 May 2007 17:57:00 +0000 http://hackaday.iheartcashews.com:8181/2007/05/19/serial-port-power-booster/#comment-26367 hum the max205 or max203 dont need caps, but it’s cost an arm or a leg for it. It’s just cheaper to get max232 and caps to keep costs low (granted a little more work.)

]]> By: Wolfmankurd http://hackaday.com/2007/05/19/serial-port-power-booster/comment-page-1/#comment-26366 Sun, 20 May 2007 13:44:25 +0000 http://hackaday.iheartcashews.com:8181/2007/05/19/serial-port-power-booster/#comment-26366 I need one of these for my pic programmer too.

]]> By: ex-parrot http://hackaday.com/2007/05/19/serial-port-power-booster/comment-page-1/#comment-26365 Sun, 20 May 2007 06:11:06 +0000 http://hackaday.iheartcashews.com:8181/2007/05/19/serial-port-power-booster/#comment-26365 That’s a fantastic idea!

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