Search found 26 matches

by skrallman
Wed Apr 09, 2003 12:18 pm
Forum: General Discussion
Topic: water sampler
Replies: 10
Views: 2001

Re: water sampler

I don't quite follow you about the 20min sample interval and changing the filter every 12hr---but I'm guessing that you mean a sequential sampler, i.e., take a sample then rotate to the next sample filter/bottle. The commercial samplers I've seen have either a rotating arm with a slip joint that rot...
by skrallman
Tue Apr 08, 2003 12:01 pm
Forum: General Discussion
Topic: need advice for multimeter with pc interface
Replies: 6
Views: 1678

Re: need advice for multimeter with pc interface

I guess I didn't really have any specific questions about the meters. Just wondering if there were any strong opinions about them. For right now I just want to monitor battery charging and discharging. I've made a NIMH battery charger but I dont think its terminating at the correct time - I've been ...
by skrallman
Mon Apr 07, 2003 10:09 am
Forum: General Discussion
Topic: need advice for multimeter with pc interface
Replies: 6
Views: 1678

need advice for multimeter with pc interface

I'm want to buy a multimeter that I can interface with my pc, primarily for data logging.
Does anyone have and experience with these or any advice?<p>CSI345 $39.95 http://www.circuitspecialists.com/prod.itml/icOid/4003
or
Radio Shack #22-812 $49.99
Thanks
Scott
by skrallman
Sun Mar 02, 2003 8:02 pm
Forum: General Discussion
Topic: Looking for PC to monitor dicharge cycle of battery pack
Replies: 4
Views: 1236

Re: Looking for PC to monitor dicharge cycle of battery pack

I'm wanting to do exatcly the same thing.
Check this link: http://home.c2i.net/proxxon/btest.html
I think you could modify this setup.
I havent built it yet. I'm waiting on the chip.
Scott
by skrallman
Fri Jan 17, 2003 10:14 am
Forum: General Discussion
Topic: Reliable No-Parts PIC Programmer
Replies: 10
Views: 2311

Re: Reliable No-Parts PIC Programmer

I made the "El Cheapo" by Myke Predko. It works fine for me.
http://www.myke.com/ and got to the El Cheapo page.
Scott
by skrallman
Fri Jan 17, 2003 10:11 am
Forum: General Discussion
Topic: Reliable No-Parts PIC Programmer
Replies: 10
Views: 2311

Re: Reliable No-Parts PIC Programmer

I made the "El Cheapo" by Myke Predko. It works fine for me.
http://www.myke.com/ and got to the El Cheapo page.
Scott
by skrallman
Fri Jan 10, 2003 7:29 pm
Forum: General Discussion
Topic: Jacob's Ladder PCB
Replies: 7
Views: 1561

Re: Jacob's Ladder PCB

Yeah, it was worth it. I'm a relatively inexperienced hobbiest, but it was quick and within my abilities. Its a neat project, but it isn't super spectacular. The sparks are only 1/4", but I still got oooo's and ahhhh's. It kind of makes you want to build something bigger - got me interested enough t...
by skrallman
Wed Jan 08, 2003 8:33 am
Forum: General Discussion
Topic: Jacob's Ladder PCB
Replies: 7
Views: 1561

Re: Jacob's Ladder PCB

I got my ladder to work. I put the timer and the coil on separate power supplies with a common ground. I also put a capacitor across the timer's positve power and ground, but I think the separate power supplies is what really did the trick. If you can't get the pcb, wire it point to point on a proto...
by skrallman
Tue Jan 07, 2003 11:04 pm
Forum: General Discussion
Topic: High Voltage
Replies: 15
Views: 4082

Re: High Voltage

Well, I can answer my own question. I put the timer and coil on separate power supplies, put a cap across the timer's power and ground and put a varistor across the MOSFET. It works. I was down to my last timer, so I tried everything. I'm getting a good spark that jumps about 1/4in, but it will only...
by skrallman
Tue Jan 07, 2003 9:13 pm
Forum: General Discussion
Topic: High Voltage
Replies: 15
Views: 4082

Re: High Voltage

I didn't realize this topic was about the Jacob's Ladder. I posted this same question in the "Jacob's ladder pcb" topic. I've made the circuit on a proto board, but I can't get it to work for more than a few seconds. I get a solid spark and it travels. After about 5 to 10 seconds the 556 or the MOSF...
by skrallman
Tue Jan 07, 2003 1:13 pm
Forum: General Discussion
Topic: Jacob's Ladder PCB
Replies: 7
Views: 1561

Re: Jacob's Ladder PCB

I've made the circuit using a radio shack proto board, but I can't get it to work for more than a few seconds. After that the 556 and the MOSFET are dieing. I'm wondering if there are some high voltage surges taking them out? I've seen similar circuits that use a capacitor between the positve supply...