Projektblogg

Senaste aktiviter visas, välj ditt projekt i menyn till höger från nedanstående projekt.

16 januari, 2019

En klimatcykel anpassad för workshops

Lars Lindmark / Projekt #027 /

Vi har fått finansiering till delar för att bygga en klimatcykel, som kommer att användas för workshops och att ta fram utbildningsmaterial

Följande delprocesser ingår i detta projekt

Design av elcykel ==> Design specifikation

Planering av workshop ==> Antal tillfällen
================> Specifikation Utbildningsmaterial
================> Behov av material och pedagogisk teknik
================> Deltagare och kommunikation

Göra utbildningsmaterial ==> Digital + utskriftsbar bok ==> iCloud Pages => Apple Book
====================> Registrera utgivare == ISBN
====================> Studiefrämjandet
====================>

Beställa delar

Hålla workshop ==> Teori
=============> Build
=============> Build
=============> Build
=============> Build

13 januari, 2019

Spot welder för batteritillverkning

Lars Lindmark / Projekt #008 / Arduino, learning, repurpose, spot welder, SSR /

Learnings from building a spot welder by Bart Oostenrijk

see attached some pictures of the spot welder. I found that a long cable (like on the picture) causes too much power loss, so I made it into a very short cable instead. The inside is an old microwave oven transformer with the secondary coil consisting of only two windings, powered by a solid state relay (AC, zero-cross switching, 40A max). When you push the small push button on the handle, the transformer is engaged very shortly, and a high current will flow at a low voltage (about 4 Volt).

There will be two successive pulses: one to ‘clean up’ and preheat the metals, and one to do the actual melting of the metals. The duration of the main pulse can be set by a potmeter.

On the pictures you can see two brass bolts I used for the contacts, but they did not seem to do the work. I then changed to copper electrodes, and they seem to work better.

The SSR is controlled by an Arduino Uno, tell me if you want the source code for that.

12 januari, 2019

First spotwelded battery by Bart

Lars Lindmark / Projekt #008 / Bart, spotwelding /

I’ve just finished my first spot welded battery. The spot welding is still tricky, but I seem to get better at it.

Sometimes I burned a hole through the zinc plate – or even into the battery, I think because of a bad copper electrode-to-zinc strip contact causing a too high temperature (fast oxidation).

I have now used full zinc strip, but it is difficult to make a strong connection at the minus side of the battery. I therefore started spot welding at the edges of the zinc strips, where the temperature rises quicker and a stronger connection was made. In the future I will try this zinc strip, because it has a small slit where the centre of the battery top will be, so that that area will become hotter quicker.

I read online that hot glue was recommended to connect the batteries, but I do not recommend it. It is a bit too weak for a glue and then the battery falls apart. Instead, these battery spacers are more robust. Off course, you can still use hot glue in between for heat transport.

The battery pack uses a a simple and cheap BMS with configuration 4p13s (48 V). With this model you get the overvoltage protection of the overall pack from charger (only charges to 54 Volt), and the undervoltage protection from the controller (stops working at 42 Volt).

Builder: Bart Oostenrijk

2 januari, 2019

uppdaterad färgkodning

Lars Lindmark / Projekt #001 / Anderson, Beta, DVDC, Powerpole, PP15-45, Standard /

Skiftat kontakt mellan 12 och 5 V, Röd är synonymt med 12V system så jag ansåg att det var ett bättre beslut. Har även lagt till Purple (Lila) för 3,3 V

18 december, 2018

Kontakt Laddbox D:2

Lars Lindmark / Projekt #003 / Modell 010, Rosenberger /

Redigera

17 december, 2018

Laddbox D:2 med relä för automatisk påslag

Lars Lindmark / Projekt #003 / 24 VDC, 42 VDC, 48 DVDC, D:2, Laddbox /

Ingångsvariabler:

Input 24 VDC
DVDC: 48VDC
Output 42 VDC

13 december, 2018

Relä Laddkontakt D:2 med Rosenberger anslutning

Lars Lindmark / Projekt #010 / Laddkontakt D:2, relä /

Plug-in miniature power relay, with power contact for high continuous currents, 1 PDT, 60 V DC. 16A

Relä 24V

Phoenix 2961341 | Mouser |Phoenix |

Relä 48V

Phoenix 2834821 | Mouser | Phoenix |

Relä 60V

Phoenix 2961134 | Mouser |
Phoenix 651-2961325 | Mouser | Phoenix | Beskrivning |

SSRDC-serien av solid-state-reläer 200V

TE Connectivity’s Potter & Brumfield SSRDC-serie av solid-state-reläer använder DC-brytarteknik med FET:er med låg effektavledning, vilket omfattar optisk koppling. SSRDC-serien används i tillämpningar med DC-last och tillhandahåller tillförlitlig DC-brytarteknik upp till 40 A och driftspänningar på upp till 200 V. Montering av värmesänka rekommenderas för att upprätthålla bastemperaturer och belastningsförhållanden.