Saturday, January 28, 2012

Power Supply variable with lm338

lm338 v.1 dual power supply

This lm338-v.1 power supply will be able to give something like two times 12- 36 volt and 2x5 amps (10 amps in the v.2 of this PSU witch includes transistors to get more current from the circuit). 

The trafos used are already able to deliver 2x 10 amps continua and 12 amps peak or so..

I use 2 x lm338 in V.1 but also lm317 can be used. I will use extra transistors to get the current up i V.2. Schematic will be equipped with current limit adjustable in steps, a current limiter with LED indicator, and i will try to find some way to make a reset able relay, than automatically disable output when short circuit or to high current drawn, Also i have some temperature sensible switches so power supply will shutdown at to high temperature on the cooling plates.

Basic DRAFT schematic from a test i made earlier.

Basic draft schematic of the dual lm338 PSU, without current limiter, short circuit protection and more

The cabinet with trafo'es, placed on my kewet electric vehicle bonnet.
The power supply is intend to be used to supply the EV when testing and adjusting lights and more optimization. No need to misuse the batteries ;)

Colling plates for the two lm338, and some pnp transistors like mj2955, or some sanken maybee

I use scraped knobs and gold plated banana plugs from a scraped nad 319 amplifier

At the side plate i have clued nappa leather

I do think this is a easy way to make functional test equipment. I will place 4 x led panel meters for voltage and amperes.

I use avery metal foil for laser printers to print the text for the front plate

 Frontplate with schorcut circuit rest, potmeters and output connectors

Shorcut protection circuit with relay in front between trafoes.


Current limit: high amp psu with current limiter 

Thursday, January 26, 2012

Reuse Scrapped VU meter as Voltage and Ampere meters

From scrapped HIFI equipment i saved two VU meters and wil use them as voltage and ampere meters for power supplyes. To messure ampere i use a pololu pcb with allegro's 30 amp hall effect linear current sensor.

In one VU meter they use two chips : LB1412 from sanyo

Specification for this chip:

  • Bar-shaped display of input level by means of 12 LEDs
  • High-order 5 dots with peak hold
  • Built-in oscillator for peak hold reset
  • Requires 1 pce. each of external C, R
  • Uses either oscillator at the time of stereo operation
  • Capable of also resetting manually
  • Capable of constant-current driving low-order 7 dots (green LED)
  • Constant-current value variable with an external resistor
  • Lower current drain available by connecting green LEDs in series
  • Built-in input amplifier
  • Requires no other light-up level adjustment than adjustment for 0 dB
  • D1 error: within ±3 dB of 20 dB
  • Supply voltage range : 10 to 16 V

In the other VU meter there is a also two chips: panasonic Dual 5-Dot LED Driver Circuit AN6888 and AN6888

AN6888/6889 is an IC driving 5 ´ 2-ch LED and is capable of logarithmic bar graph display for input signal.
Incorporating high gain rectification amp. enable to apply VU/Signal meter widely.

Because the output is the constant current pull-in type, the constant current value can be variable by external resistance. n Features

I am not sure what the difference is between the two types but i found a schematic:

Specification for this chipset:

  • Wide range of operating voltage : VCC (opr.) = 5V ~ 16V 
  • Power consumption can be reduced due to series connection of LEDs
  • Wide range of constant current : 5mA ~ 25mA
  • Built-in high gain amp. : GV = 26dB typ.

DC motor driver 9 ampere - 30 ampere peak

Found cheap PCB with ST VNH3SP30 motor driver IC It operates from 5.5 to 16 V and deliver continuous 9 Amps and 30 Amps peak! The PCB board offers built-in protection: against reverse-voltage, over-voltage, under-voltage, over-temperature, and over-current. I will check this PCB out some, maybee useful for my DIY electric bicycle

Sunday, January 22, 2012

Arduino source code for StokerArduino v1.0

The project: pellet boiler datalogger v1.0 homepage is found here Arduino Pellet Boiler Data Logger v1 My Nerd Stuff

This is the code for the arduino only, you also need save.php to place on the (LAMP) webserver and if you wish to save data in thhe database the mysql must be setup properly to work. You can also choose to save data in a file only. This files name is data.txt.

Read more about how the ethershield i use works here:

I will make a better descrribtion some day, with block diagram of how this works


dallas ds18b20 codepiece and howto connect to arduino

EVduino-ms beta shield

The power supply with lm317 to protect EVduino from spikes in the EV

EVduino-ms beta optocoupler batteri voltage sensor

The beta version with standard 5% resistors, in final version use 1% or better.

I use 15K resistor inseries with the optocoupler LED and conect this direkt on the batteri (red and black wire).

The 3 pins behind the cny 17 runs trouh a double shielded cable to to EVduino-MS.

Between +5 volt and the cny17 opto's collector there is a pull up resistor 20K 1%.

The voltage of a lead acid battery are:

12,8 volt: fully charged
10,5 volt fully discharged

Other solutions for measuring battery voltage with arduino:

1 wire technology, DS2438 messure battery voltage AND battery temperature, great for LiFePo4 batteries in the EV

Also i will try to test a linear opto circuit found online before i deside how the final version shoulld be.

Saturday, January 21, 2012

Arduino based Electric Vehicle Monitoring System - The EVduino-MS

Arduino Electric Vehicle Monitoring System - the EVduino-MS-08b

  • Project start: 20 January 2012
  • Current version: 0.8 Beta
  • Project name: EVduino-MS
  • Licence and copyright: GPL open source
Update 23/1-2015: more about this kewet 2 electric vehicle

This Monitoring System is intend to be used in my KEWET 2 Electric Vehicle with 48 volt system voltage:

It can be used in all other Electric Vehicles. Just need to ad more opto voltage sensor circuits and make som more code. Also you need to make multiplexed analog input because there are only analog inputs for 14 batteries.

Block schematic looks something like this. This is preliminary version, you can't trust component values and more. Only made to tell something about the concept:

Project Status:
Main control unit:

DFRduino Mega 1280
2,8" LCD touch color monitor with onboard SD card reader
EVduino beta shield.
All build into 2  pcs. 7010 25 mm half box. The Size of one half box is: 123x70x26,1 mm.

I will make some kind of fancy front plate with some text on it, properly just 3 mm acrylic with silver laser label on it (avery L6013)

Connectors will be 3.5 mm jack gold, or a 25 pins sub-d gold connector or so.

Version 0.8 beta will include: EVduino-MS-08beta Arduino Code workbench 

Specifications DFRduino 1280:
  • Microcontroller ATmega1280
  • Operating Voltage 5V
  • Input Voltage (recommended) 7-12V
  • Input Voltage (limits) 6-20V
  • Digital I/O Pins 54 (of which 14 provide PWM output)
  • Analog Input Pins 16
  • DC Current per I/O Pin 40 mA
  • DC Current for 3.3V Pin 50 mA
  • Flash Memory 128 KB of which 4 KB used by bootloader
  • Clock Speed 16 MHz

Specifications for the 2,8" LCD touch color monitor:
  • The 2.8" TFT color LCD shield with touch screen interface
  • 320x240 screen resolution
  • 65K color space
  • touchscreen interfac
  • on-board AD7843 compatible controller
  •  SD card interface in SPI mode for external mass storage of photos and icons
  • Directly plug into Arduino Mega
  • Arduino software library included, also examples of graphic and font routines, touchscreen interface and calibration, and SD card (FAT filesystem) operation

Port usage:

Digital I/O Pins 54: 
  •   Digital ports 22 to 53 used by Touch screen, Lcd monitor and SD card
  •   PWM port 2 to 13 I/O provide PWM output, all free to use
Analog Input Pins 16:
  •   All 16 AD converters are free to use

The DFRduino Mega, Analog in 0 to 15 below at the picture and the free Digital I/O 2 to 13 With PWM on top left

The sensors and hardware:

High current sensor 300 Amps from

Temperature sensor one wire Dallas ds18b20, from and more 

Opto isolators cny17, from, or all around electronic stores

The full 'Vision' is a version 2.0 of this Arduino EV monitor system EVduino-MS-Pro2

The pro2 version should include a professional print layout of the shield, build into a box. A finished, tested and adjusted Plug and Play box.

Also a DIY version could be made, i could call it version DIY-Pro2, incl. box with all hole made to it, components and more.

Sensors in The fully Pro2 developed version of the EV Monitor system:
  • up to 6 pcs. Voltage sensors for 6 x 12 volt battery packs
  • 1 pcs. current sensor 300 ampere, battery total
  • 6 pcs. battery temperature sensors
  • 1 pcs. engine coil temperature sensor
  • 1 pcs. indoor temperatur sensor
  • 1 pcs. outdoor temperature sensor
  • 1 pcs. tilt sensor for burgler alarm
  • 1 pcs. RFID chip sensor as carkey

Other features:

Blinking LED are automatically activated when a person with the 'carkey RFID' leave the car
Also a buzzer is connected as intern alert and alarm
Relay output to turn of lights and more automatically

Power supply:

Li Ion powered by Accessory power supply
Solar-charger with 30-60 watt solar-panel
Waist heat Thermoelectric Energy Generator charger (waist brake heat, engine heat and motor-controller heat)
remote on/off liquid fuelbased heater

Further adds to Arduino Monitoring system for electric vehicles:

* wifi connection to LAN
* webpage including graphs
* android app

Sunday, January 15, 2012

PWM dc motor controller with current limiter

This is a version with current limiter, the bd435 transitor pull gate on fet down, and motor current fors down. You must adjust the resistors to fit your motor current.

This is another version where the current limiter is inactive, and turn on a LED. It Will then be possible to makeup sure that i run the e-bicycke in a low energi consumption mode, so I can drive more km on a charge.

You can also ad more n-fets for better stability and less watt/heat loss in the fets rON stage


check out pololu's H-bridge moter driver board

PWM DC motor controller for DIIY electric bicycle

I started this project because i got hands-on a 50 Watt Bosch DC PM motor with bicycle gear mounted to it.

Update 23/1-2015: Repair liion battery for Electric bicycle, and how to dissemble a hub motor on a electric bicycle 

Bosch DPB24V 0 130 110 015 24 volt 50 watt DC motor

I have a old rarely used mountain bike made of aluminium, i  think it would be great to convert it to EB = Electric Bicycle.

I've made a luggage carrier of 6 mm solid steel, so that it is stable enough for the electric motor

i was disappointed to see the electric motor is with coal, thought really it was aconstant magnet motor

I made a bracket to hold the electric engine tight

Electronic for the DC Engine

I made a simple DIY PWM DC motor controller using NE555 and N-FET from scrapped computer

Bosch DPB24V 0 130 110 015 24 volt 50 watt DC motor with control electronic incl. Speed potmeter.

This is my version of the PWN DC motor controller. The schematic is based on some standard PWM Motor controller schematic found in google picture search

This is the circuit, i will make a filtering circuit latter, and fill up the space on the pcb, below components.

Spray with Lötlack SK10 or use molding compound to weather protect the electronic

Check out my DIY conversion of my old Mountain Bike to electric bicycle with the PWM DC motor controller circuit made in the post.

Check this movie for a demo of this Motor controller:

Links and ressources:
60Amp PWM DC controller
wiki about PWN
PWM controller filtering
Another version of this PWM DC motor controller
Molding compound for weather protection of the pcb
Lötlack SK10