Saturday, December 31, 2011
Friday, December 30, 2011
I tryed this in 2009, using front plate of the Pellet boiler as heat source for the thermoelectric element (peltier). I burned more than 5-6 of them to dead, the plate temperature went op to more than 180 c .
So, now i made a air space gab at 1 mm to the hot plate, and automatic temperature protection. A gear motor will turn peltiers away from the plate if more than 100 c comes to the peltirs surface.
Friday, December 23, 2011
'solar charger circuit that is used to charge Lead Acid or Ni-Cd batteries using the solar energy power. The circuit harvests solar energy to charge a 6 volt 4.5 Ah rechargeable battery for various applications. The charger has Voltage and Current regulation and Over voltage cut off facilities'
Monday, December 12, 2011
Monday, December 5, 2011
1: buy inductors with colorcode
2: Use a tonegenerator and a osciloscope to calculate inductance : http://et.nmsu.edu/~etti/fall96/electronics/induct/induct.html
3: Build a L meter / Induction meter http://apexys-toan.blogspot.com/2011/02/ne555-based-inductivty-meter.html
Below i build the inductance meter found at apexys-toan blog.
The schematic is borrowed from the projects homepage, hope this is ok, I will remove the schematic immediately on request from the author.
coil color code
In the original project a 40uA / 2500 ohm meter is used, my meter is 100 uA and 1000 ohm, and works well. I am not sure how to calculate the scale. I found tree inductors vwith colorcode on and plottet them into the scala. I have desided to buy cheap small inductors in different values, to calibrate the scale.
The ne555 at work
Wednesday, November 23, 2011
You can use any kind of load: relay driver, fet switch, LEDS, bulb and more. Design the load driver so the optocoupler is driver for the 'driver transistor' ;)
This circuit can be used as undervoltage detector for LiPo batteries, Li ion bateries and more.
I use this circuit in my automatic grid of offgrid power strip
Monday, November 21, 2011
Update 25-12-2011: added a 3k9 resistor in series with the trimpot, the trimpot burned at low resistance
lm2577 step up converter to be used for my TEG peltier power generator mountet on my pellet boiler.
I decided use this step up converter schematic as base circuit:
Works in first take ;)
I works, but i am not satisfied with the performance. There are lot of lost power in power conversion with this chip, as i only has a standard NPN transistor as switcher instead of a MosFet.
So i will DIY my own switcher circuit for my TEG ;)
Sunday, November 20, 2011
The peltier elements (the white layer between the copper plates) are placed between cobber top plate with pipes for cooling water inside
This show the power block with step up converter. Made to stepup from 1,5 volt tol 9 volt to charge a 6 volt akku.
I found a cheap vaterpump wheel i will try to use in a more power full water cooler driven by PMM with neuro magnets: http://biltema.dk/da/Bat/Pumpe/Vandpumpe/Vandpumpe-12-V-25988/
Saturday, November 12, 2011
Maximum performance was 471 watts a sunny winter day here in Denmark. The total power from 2 pcs 190 watt ulica solarpanels are 1140 watts. So 471 watts are great winter power i think. I use 375 watt in average every hour, so just a little sunshine in the daytime, and my electricity needs are meet.
Monday, November 7, 2011
When i turn on this power strip it automatically detects lowvoltage on tofgrid batteri'es, and chose to turn on the inverter or switch on relay to grid as power source. Also, if low voltage is detectected when i watch television, i switch to grid from offgrid, an stay gridtied to next time power strip is turned on.
To stay safe it has build in two optocouplers, to protect agains 220 volt in the 12 volt offgrid system.
Link to the under-voltage detector circuit
The control circuit on pcb:
This is how i works:
The idee in blocks
My 12 volt to 220 volt inverter:
The power strip and the inverter
I tryed to yúse a simple Set / reset flip flop with transistors, to hold relay, but it was unstable, so i desided to use a small relay with low power consumption instead. You can try to build this circuit to experiment with transistor based set reset logic:
Sunday, November 6, 2011
It has aluminium chassis, and is light weight. Wheels are 26".
I will convert it to electric bicycle.
Step conversion DIY guide
- Make a simple DIY PWM DC moter controller with FET from scrap components, Done
- Make a some kind of magnetic sensor (hall) that can measure than the pedals run round
- Make some kind of brancket for the motor, and batteries
- Make a 24 Volt battery pack from scrap Laptops Li-Ion bateries
- Make a 24 Li Ion Charger with temperature sensor, anti fire protection and more
Thursday, November 3, 2011
his article is my workbench 'Notepad' as i learn and build a buck bost inverter for low voltage from peltier elements seeberg effect (thermoelectric elements) and solarcells.
Both power sources give very low voltage: solarcells typical 0,5 volt and peltier elements 0,5 - 1-2 volts.
My goal is to charge directly on a standard acid battery, both 6 volt and 12 volt.
Latter i will add a Li Ion / LiPo single cell charger and a charger on mulitible Li cells cells
I've saved some defective PC computer power supplies for spare parts, they have quality great coils and more.
I believe i can find all parts needed on these pcb's to build my buck boost chargers
Chips found on deffective boards:
- uc3844 Current-Mode PWM Controller
- uc3842an High Performance Current Mode Controller
- 2 pcs top210pfi Off-line PWM Switch
- Ka7552 pwm controller
Tuesday, November 1, 2011
I found the schematic for stepup converter 12 volt to 24 volt here
- Version 1.0: this version i not covered on this site you can follow the 12 volt to 48 volt solarcharger stepup converter here
- Version 0.8 beta: The version below show my first stepup converter experiment with uc3842. I 'killed' 2 uc3842 in my experiments increasing output voltage to 48-60 volt for my EV, så desided to build a new version, version 1.0
It works as expected, mppt starts charge at 15 volts, not sure why not 10 volt, but output voltage is stable 24 volt. When i turn input voltage up to 20 volt still 24 volt output, i turn down insteps to 10 vlt, still 24 volt output, and when i stay between 10 volt and 20 volt it works totaly as i expected, Great mppt to my diy solarpanels ;)
Some link and ressources:
Monday, October 31, 2011
Original Schematic to this simple and effective switcher can be found here: http://freecircuitdiagram.com/2010/05/22/small-dc-dc-inverter-convert-1-5-to-9-volts/
I decided to make a MosFet based version for better performance. Update follw later opn this subject ;)
Think i will experiment with my fridge, build in som peltiers to help the compressor to cool down food with cheap DIY solar panels.