Re: [tracker2] Power From Laptop
- If I recall correctly, the rs232 spec says there is a 300ohm resistor in series with each output pin. It's a current limiter by default. Should give about 40mA. Very often, you can rewire an output pin to put 12v on it... the good news is that +/-12v is safe on rs232 due to a 3k ohm input impedance on any device you would plug in... so it won't fry your TNC or serial mouse.I have to agree with another poster... safer bet is to leech power from USB.WesOn Mon, Feb 2, 2009 at 1:39 PM, Adam Sherman <adam@...> wrote:
You can't get rid of poverty by giving people money.
It may be necessary temporarily to accept a lesser evil, but one must never label a necessary evil as good.
- On Mon, Feb 2, 2009 at 1:30 PM, Fred Hillhouse <fmhillhouse@...> wrote:
> 100mA is usually no problem and possibly up to 400mA. But there is noThe USB spec says any peripheral gets 100mA by default. Up to 500mA
> guarantee above 100mA.
may be available, but it requires some negotiation to get more than
In reality, I think some ports just give you 500mA.
- On 2-Feb-09, at 13:39 , Adam Sherman wrote:
> Is it possible to get power via the serial port on a laptop?Thanks for the overwhelming amount of replies!
The end conclusion is that a serial-USB adapter than would power the
Tracker should be possible. I'm going to investigate.
- I made a pigtail on the null-modem cable for OT+, with a short cable to plug to the USB port of the laptop, to tap the 5V line (leftmost pin) and deliver it to Pin 4 on the DB9 to OT1 series (or OT2m).73 de Paulus N5SNN / YD0NXX
--- On Mon, 2/2/09, Adam Sherman <adam@...> wrote:
From: Adam Sherman <adam@...>
Subject: [tracker2] Power From Laptop
Date: Monday, February 2, 2009, 12:39 PM
Is it possible to get power via the serial port on a laptop? Thanks, A. -- Adam Sherman me@... VA3SHR ------------------------------------ Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/tracker2/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/tracker2/join (Yahoo! ID required) <*> To change settings via email: mailto:email@example.com mailto:firstname.lastname@example.org <*> To unsubscribe from this group, send an email to: email@example.com <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/