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Topic: Your latest purchase (Read 124086 times) previous topic - next topic

Osgeld

what are you using that to measure current on?
http://arduino.cc/forum/index.php?action=unread;boards=2,3,4,5,67,6,7,8,9,10,11,66,12,13,15,14,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,86,87,89,1;ALL

Nick Gammon

I had used it to measure the draw from a 12V battery as part of a UPS system. Never got it quite working perfectly.
Please post technical questions on the forum, not by personal message. Thanks!

More info:
http://www.gammon.com.au/electronics

wizdum



Finally got everything dusted off and started testing. No idea what i'm going to do with it yet. Will probably make an arduino environmental monitor for it. The little 8+1 port switch is just for testing purposes, I need to rewire all the jacks into that room before I move my 24 port gigabit switch in there. The orange on the top is about 300 feet of fiber optic cable, with six media converters.
"Anyone who isn't confused really doesn't understand the situation."

Electronic props for Airsoft, paintball, and laser tag -> www.nightscapetech.com

JoeN

I have only come here seeking knowledge. Things they would not teach me of in college.

wizdum

"Anyone who isn't confused really doesn't understand the situation."

Electronic props for Airsoft, paintball, and laser tag -> www.nightscapetech.com

retrolefty



A 0.001 ohm resistor.




1/4w or 1/2w?

It's rating would be 10 watts. 100 amps X .1 volts drop.

Lefty

wizdum




A 0.001 ohm resistor.




1/4w or 1/2w?

It's rating would be 10 watts. 100 amps X .1 volts drop.

Lefty


And another joke ruined by proper labeling, darn.
"Anyone who isn't confused really doesn't understand the situation."

Electronic props for Airsoft, paintball, and laser tag -> www.nightscapetech.com

Nick Gammon


How do you even test that?


Not that easily. :)

Various measurements have given somewhat different results. I think the lugs have probably got a bit of resistance in them.

I tried passing 5 amps through it, but measure about 75 mV between the terminals, which doesn't sound right.
Please post technical questions on the forum, not by personal message. Thanks!

More info:
http://www.gammon.com.au/electronics

GoForSmoke

Maybe the time to fill a big R-C circuit both without and with that resistor would show something? But that would depend on how steady the power going in would be.

Nick Gammon on multitasking Arduinos:
1) http://gammon.com.au/blink
2) http://gammon.com.au/serial
3) http://gammon.com.au/interrupts

Nick Gammon

I tried again with a firmer connection to the resistor and doing a Kelvin measurement. Still got 8.8 mV with 4A going through it, so out by a factor of 2 as far as I can see.
Please post technical questions on the forum, not by personal message. Thanks!

More info:
http://www.gammon.com.au/electronics

aarondc

A quick appraisal of my online electronics purchasing experience to date:

sparkfun.com: good product descriptions, reliable stock levels, quick feedback due to credit card processing being broken, but then fixed a day or so later. Good notification and delivered in a week. Sparkfun's packing department are incredible.
futurlec.com: order still not shipped after 2 weeks. replied to email enquiry within a day to say 7 items from my order are out of stock and will not be in stock for 1-2 weeks, when my order will be dispatched. website currently lists all 7 items as in stock.
dx.com: charged my credit card twice for the order. has apparently dispatched 3 shipments making up the complete order, but so far nothing has arrived (10 days since first shipment notification).

2 x ebay sellers (1 China, 1 Aussie) have shipped products asap and received them within a week.
Another ebay seller has shipped but via cheap shipping (US), so still waiting for the order to arrive (10 days and counting).

Windows serial port monitor: Tellurium | Arduino serial port debugging library: DBG | Cusom LCD char generator | Technical questions will only be answered in forum threads

GoForSmoke

I remember a place in Australia called Dontronics that had a scheme called Simstick. I liked the idea of putting chips on like-memory cards in a small bus.
I did get a dev board for AVR 90Sxxxx chips from them but RL stepped in and next thing I knew Arduino was available.

Does anyone Down Under know Dontronics? I do wonder how many places like that there are in Australia and how good a country it is to run a small to medium business out of?

Nick Gammon on multitasking Arduinos:
1) http://gammon.com.au/blink
2) http://gammon.com.au/serial
3) http://gammon.com.au/interrupts

aarondc

Never heard of them, so checked them out. Interesting site. Can't really tell what they're selling though. Layout is not the easiest to follow after sparkfun spoiling me with pics and descriptions.

Electronics SME in Australia not that great, imo. Market is tiny, international postage costs are steep, shipping components in can be expensive. If I had a good idea that would sell, I'd probably go to the US to do it first.

Love the place though, wouldn't trade it for anywhere else.
Windows serial port monitor: Tellurium | Arduino serial port debugging library: DBG | Cusom LCD char generator | Technical questions will only be answered in forum threads

GoForSmoke

Got another order in with Yourduino.
Note that the chips and thermistors are package of 5 for from 75 cents to $1.50.


Order Summary:
Product    
Qty    Price    Subtotal
========================================
2.4GHz Transceiver Low Power nRF24L01+
2    $2.75    $5.50

AC Line Power Supply: 9V 1A
2    $3.00    $6.00

AC Line Power Supply: 3.3VDC 2.5A
1    $4.50    $4.50

5.5mm x 2.1mm Plug for Arduino External Power Connector
4    $0.35    $1.40

LM324 4x opamp (single supply) (Pkg of 5)
2    $0.75    $1.50

LM386 Audio amp low-voltage (Pkg of 5)
2    $0.75    $1.50

NE5532 Low Noise Dual Op Amp (Pkg of 5)
1    $1.50    $1.50

74HC165 8x Parallel-In Serial-Out Shift Register (Pkg of 5)
1    $1.50    $1.50

Thermistor 10K (5ea)
1    $1.25    $1.25

AC Line Power Supply: 5V 1A
1    $2.50    $2.50

Subtotal:    $27.15
Shipping:    $15.00
Tax:    $0.00
Total:    $42.15
========================================================
Nick Gammon on multitasking Arduinos:
1) http://gammon.com.au/blink
2) http://gammon.com.au/serial
3) http://gammon.com.au/interrupts

aarondc


Got another order in with Yourduino.


What's their stock level / shipping time like?
Windows serial port monitor: Tellurium | Arduino serial port debugging library: DBG | Cusom LCD char generator | Technical questions will only be answered in forum threads

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