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16  Using Arduino / General Electronics / Re: MC34063 Boost w/ external NPN not starting up on: August 25, 2014, 12:52:30 am
I cant figure out how to upload files on this forum.
If you can send me your email address, Ill send you the LTspice model for the MC34063.
My email address is mauried@tpg.com.au
17  Using Arduino / General Electronics / Re: MC34063 Boost w/ external NPN not starting up on: August 24, 2014, 06:26:06 pm
Boost converters draw more current when they start, than when they are running, as when the converter starts
its looking into charging the output capacitor which looks like a short circuit initially.
If you dont get anywhere, I suggest you download LTspice4 , http://www.linear.com/designtools/software/?gclid=CJOJ2aaFrcACFcQHvAodG1oA_Q#LTspice

and simulate your circuit.
You can them measure the peak inductor current at start time and run time .
18  Using Arduino / General Electronics / Re: MC34063 Boost w/ external NPN not starting up on: August 24, 2014, 03:53:46 am
I use this design tool to calculate the optimum values for MC34063 switcher circuits.
http://www.nomad.ee/micros/mc34063a/

It gives you the optimum values, for any config , Buck,boost or inverting.
The important value is the Inductor peak current , as it determines what the inductor size
needs to be to avoid saturating.

19  Using Arduino / General Electronics / Re: MC34063 Boost w/ external NPN not starting up on: August 23, 2014, 08:17:36 pm
Ok, all I can suggest is you try another switcher chip.
Normally if the triangle wave generator is running, but no switching is happening
then either Q1 or Q2 in the switcher chip is fried.
Its usually Q1 that goes.
Id try just using another MC34063 just by itself without an external pass transistor
and Id also suggest you increase the Inductor value to at least 150 uH with the same saturation
current as the existing inductor.
33 uH is very marginal at startup.
20  Using Arduino / General Electronics / Re: MC34063 Boost w/ external NPN not starting up on: August 23, 2014, 06:09:17 pm
See if you can measure the resistance between pin 1 and pin 2 of the MC34063.
You will have to disconnect one of the pins from the rest of the circuit to do this.
This is to determine whether the switcher transistor , Q1 in the chip is fried.
You should get very high resistance.
21  Using Arduino / General Electronics / Re: MC34063 Boost w/ external NPN not starting up on: August 23, 2014, 05:09:03 am
Whats the maximum and minimum  load current?
22  Using Arduino / General Electronics / Re: MC34063 Boost w/ external NPN not starting up on: August 22, 2014, 11:58:54 pm
Sounds like a stuffed transistor, but the issue will be what broke it.
No switching sounds like the main switching transistor Q1 in the MC34063 is also stuffed.
Whats the saturation current of the series inductor?

23  Using Arduino / Project Guidance / Re: RF Link Kit problem / Virtual Wire on: August 22, 2014, 01:22:26 am
You have bought the wrong RF link kit.
That kit has a encoder and a decoder on the board with the transmitter and receiver.
Its most likley based on the SC 2262 / SC 2272 4 bit data encoders, which can send a 4 bit value from one to the other.
You dont need Virtual Wire.
To send an 8 bit value , you will have to break it into 2 , 4 bit values , and then send the 4 bit values one after the other.
24  Using Arduino / Motors, Mechanics, and Power / Re: Arduino Mega hanging on Solar Power on: August 21, 2014, 05:57:49 pm
What do you mean by this
"switch over from solar PV module to Battery"
With any Solar Powered system, the battery should provide the power all the time.
All the Solar Panel should do is charge the battery.
There should never be any switchover from the battery to the Solar panel.
A circuit diagram would help.
25  Using Arduino / Project Guidance / Re: product with Arduino and a kind of VirtualWire library on: August 20, 2014, 02:45:45 am
Yes, the OPs question makes no sense at all.
What are you trying to do?
26  Using Arduino / General Electronics / Re: Unconventional/alternative battery recharge? on: August 19, 2014, 09:47:40 pm
Thats a very small capacity battery.
How much power does your robot need?
27  Using Arduino / Project Guidance / Re: Multiple arduino's sending information via 2.4ghz or 433mhz? on: August 17, 2014, 06:02:36 pm
Its preferable for a setup like this to try and avoid having bi directional transmissions, as it requires having receivers
running all the time at the sensors, which eats up the power.
Outdoor sensors are easier to install if they can run on batteries.
A common technique that a lot of weather stations use, is to transmit their data at regular intervals, that are differant
for each sensor.
eg 1st sensor sends data every minute, 2nd sensor sends every 70 seconds, 3rd sends every 80 seconds etc.
This avoids data corruption from sensors interfering with each other.
If the sensors use a 32.768 khz watch crystal as the clock, then you can get accurate timing for the data sending.
28  Using Arduino / Project Guidance / Re: House plant watering bot on: August 16, 2014, 05:22:53 am
You still need a failsafe system , regardless of when the last watering happened.
What happens if the Arduino crashes whilst the water pump is running.
29  Using Arduino / General Electronics / Re: Old Computer Power Supply on: August 15, 2014, 09:16:31 pm
CD drives draw most of their power from the 12V rail.
Only the low level logic uses the 5V rail, so if the drive isnt doing anything , like reading or writing
it wont draw power from the 5V rail , which is what you need.
30  Using Arduino / Project Guidance / Re: Easy to use rf transceiver chip. on: August 15, 2014, 06:34:40 pm
Your question makes no sense.
What do you mean by , you dont want to use a pre made module.?
Do you want to build your own module , in which case forget it, its too complex a task.

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