Recent content by Solar Mike

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    Compact PWM PV Charge Controller using 08M2

    I have also created an alternative variant of this low power PWM controller using a PICAXE 14M2, it used shunt PWM regulation and will have lower standby power when not under charge, which maybe more important for smaller batteries; also has extra leds showing charge status. Look over on The...
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    help on code (closed)

    Should not be using brackets, and incorrect variable definition used, look at the examples in the online "Basic Commands" eg. Symbol variableA = w0 Count C.2, 25000, variableA
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    PICAXE-08M2 DAC sample rate

    Whole purpose is to repeat the command sequence DacLevel 31 : DacLevel 0, fifty times, rather than having to type out several lines of code.
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    Compact PWM PV Charge Controller using 08M2

    Here is a picture of a the built up board used for initial testing.
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    Compact PWM PV Charge Controller using 08M2

    Finally have some software, attached as zip file. Code is well commented, so I won't elaborate further here. Have given the code and the board a good test, all works as expected, no changes required to pcb layout. For the 12v gel battery I was using and the 30watt PV panel, resistors R1 = 20k...
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    Compact PWM PV Charge Controller using 08M2

    PCB's are back, have made one up for testing, looks ok no errors, writing software for it now.
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    Compact PWM PV Charge Controller using 08M2

    PCB 72x60mm: Gerber files Attached. I am waiting for the pcb's to come back, will then test it and write some software, post back here later. Cheers Mike
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    Compact PWM PV Charge Controller using 08M2

    Here is a basic design for a PWM type PV solar charge controller, using a Picaxe 08M2. Ideal for smaller 30W panels charging a 10AH or so lead acid battery. I have a number of projects coming up that require small panels hooked up to various size 12 volt gel or Lifepo4 batteries, in stand alone...
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    PC board fabs

    Diptrace is very easy and intuitive to learn, the lite version is free for non-profit use, send them a note to get the download link. Link: DipTrace JLCPCB are where I get my PCBs made, very inexpensive, the cheapest shipping option, airmail courier takes about 10 days delivery to NZ. Export...
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    PICAXE Mini Mppt 12v Battery Charger

    Have also implemented a PWM only version, same 100 x 100mm foot print, using two or four back to back mosfets; this is for those smaller 18v PV panels where MPPT would be an over complication. With suitable extra thick wires soldered to the pcb, and the additional mosfet pair, current could be...
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    PICAXE Mini Mppt 12v Battery Charger

    Here is a small Mppt charger designed specifically for 12 or 24 volt batteries, I wanted a minimal system fitting on a 100 x 100mm pcb that will handle a PV panel up to 150-200W and voltages of 70 volts or so. Thought it may be of interest to some members here, components are getting very hard...
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    Alternator W terminal to picaxe

    I used to build and install genset control systems for large multi KVA diesel generators, to get a reliable feedback signal to indicate the motor was running (turning over), we used a magnetic coil sensor placed near the starter motor flywheel teeth. If the engine was running at all, this would...
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    Measuring the power of sine and square waves.

    You could use a hall effect current sensor like the ACS712 series, Sensor Link Place it in series with your speaker to measure the current at various audio frequencies at the corresponding speaker non-linear impedance. Take a voltage measurement at the same time and multiply the two together...
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    Serial LCD display for PIC projects ?

    Alternative serial display drivers (Google LCD #117) that work at 19200 baud are readily available if you need a faster device. Cheers Mike
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    Picaxe 28X2 200v 30A Mppt PV Controller

    Only few minor changes on the pcb which is good as the layout was done from memory with no actual circuit dia; so drawing that sorted out any issues. I will post the gerbers of the little filter modules, I use them everywhere where noisy analog signals must be read by an ADC. Gerbers...
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