Blog - All Comments

RE: OpenWindow: open-source car electric window controller

mp2100 — Sat, 17 Oct 2020 15:51:13 GMT

nIce project. Having paid full price plus labor for a mechanic to replace a window controller, it’s good learn what you have worked out. One question, did you measure typical ‘floating’ voltages when the window was not moving? If it’s floating, it seems the voltage could find its way to 0 volts by acccident, and that would open the window.

RE: Fire Extinguisher Car

robogary — Fri, 16 Oct 2020 16:45:15 GMT

your fire truck made me smile.

I would take this to the local coffee shop, re-fill ladie's coffee and tea cups as a way to introduce myself.

Its also a fun way to water plants.

RE: Yummy yogurt with temperature control

three-phase — Thu, 15 Oct 2020 21:13:54 GMT

Nice project and well written blog, hopefully you will be able to spend some more time on it to progress it further.

Kind regards

RE: Smart Solar Lighting Project - LED Intensity Control System

fmilburn — Thu, 15 Oct 2020 03:57:06 GMT

That's a nice video demonstrating how well the system works Gene. It is a great project too.

Frank

RE: What's cooking with that reflow oven of yours (part 2)

genebren — Wed, 14 Oct 2020 22:20:59 GMT

Well done! Nice to follow along on your journey as you did some great troubleshooting and discovery.

RE: Yummy yogurt with temperature control

DAB — Wed, 14 Oct 2020 18:48:37 GMT

Nice analysis.

Sometimes you have to be careful with the overshoot and take a slower temperature ramp up.

DAB

RE: What's cooking with that reflow oven of yours (part 2)

DAB — Wed, 14 Oct 2020 18:43:49 GMT

As long as you learn a lot, you have a successful project.

DAB

RE: Simple Electronic Control Systems - Current Control with 1 transistor

ChrisDancer — Sun, 11 Oct 2020 17:11:32 GMT

One problem with this circuit is that the base- emitter voltage of the transistor and the forward voltage of the diodes will change with temperature, which will cause the current to vary. You can reduce the temperature dependence of the curcuit greatly by using an ordinary red LED in place of the 3 diodes. The change in the forward voltage of the LED with temperature is roughly equal and opposite to that of the transistor junction.

The forward drop of the LED will be about 1.8 V.

RE: What's cooking with that reflow oven of yours (part 1)

shabaz — Sat, 10 Oct 2020 16:54:38 GMT

Hi Colin,

Awesome project!

I think my (ancient, ebay purchased) reflow oven (which I barely use for prototypes, since it's quite large it's stored away in a nearby basement) has halogen or ceramic tubes too. Before I got that, I wanted to make one, and was considering using a mix of ceramic and IR elements.

If you want them, let me know and I can post them.. purchased them from a company called Ceramicx. Probably got a short length of heat-resistant wire and connectors too.

Another idea (might not work!) was that if just a single painful component needs to be reflowed (and if the remainder can be done by hand soldering) I was curious if a 12V lighting transformer, and a little MR16 or GU10 halogen bulb could work (might need some heat-resistant transparent cylinder. Finding that heat-resistant transparent cylinder is a problem preventing testing that out!

RE: What's cooking with that reflow oven of yours (part 1)

phoenixcomm — Fri, 09 Oct 2020 20:30:52 GMT

[mention:18d073d7306a4a8694ee59c07b9ecc65:e9ed411860ed4f2ba0265705b8793d05] Nice blog and you show your thought process.

~~Cris

RE: What's cooking with that reflow oven of yours (part 1)

DAB — Fri, 09 Oct 2020 19:38:24 GMT

Nice post.

I would not have thought about modifying a slow cooker, they are usually just used to bring a large mass of food to about boiling.

I look forward to seeing how you procede.

DAB

RE: What's cooking with that reflow oven of yours (part 1)

michaelkellett — Fri, 09 Oct 2020 08:47:00 GMT

I have an expensive CIF reflow oven which uses IR heaters and a circulating fan.

When powered the heaters light up just like your halogen lamps - (really bright white light).

The controller used in the CIF seems to turn the heaters on or off at full welly, achieving control by modulating the ratio of on to off time.

Minimum on time seems to be less than 1 second (I'll measure it if you ask me).

So I reckon you could re-create the CIF with your halogen light, a metal box inside a second metal box with insulation in between.

Then a mesh support for the board half way up and a fan to whiz the air about.

Thermocouples are the best sensors for this work, cheap, small (for fast response) and can take the temperatures.

[View:/resized-image/__size/620x415/__key/commentfiles/f7d226abd59f475c9d224a79e3f0ec07-5be3f157-b6b1-44cb-8e6b-fed0b221f888/6052.contentimage_5F00_192695.jpg:620:415]

Looking at the window with the heaters on - bright white light

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Attempting to get picture of the heaters when on but they cool very fast when the drawer is opened.

You could use something like Farnell 2770605 to switch the power to the halogen bulbs.

(You can buy a temperature controller with a solid state relay from AliExpress for less than the SSS from Farnell - I have done so in the past and some of them work OK.

Quality and adherence to standards is conspicuous by its absence.)

RE: What's cooking with that reflow oven of yours (part 1)

pappy1 — Fri, 09 Oct 2020 02:35:22 GMT

I'm currently in the process of building one, my design however comes from a local magazine Silicon Chip. Have a look at issues April and May 2020. Only drawback is it uses SMDs, and as the author says would be handy at this point to have a reflow oven. Nonetheless not too many SMDs that they can't really be done by hand. Some later issues indicate that others have built it and it works well. As the power supply for the controller is done by a plug pack and the oven control is done by a solid state relay and a thermocouple in the oven it should work well with different AC voltages and currents used in different countries. Some modifications may only be needed for the solid state relays (although the 240V 40A ones specified should be enough for anywhere) and the local AC plug fittings.

RE: What's cooking with that reflow oven of yours (part 1)

genebren — Thu, 08 Oct 2020 20:37:27 GMT

Nice blog of the development process. There are always twists and turns along the path.

I had a friend who had tried several of these steps (toaster oven to Halogen flood light). From what I recall, the flood light came really close to meeting his needs, but still had issues. I believe that there are some tutorials/blogs out there that present some workable designs.

Good luck!

RE: Running in circles ? Make it perfect circles with regulators

jw0752 — Wed, 07 Oct 2020 19:57:12 GMT

Hi Gary,

I found your experiment and work to get the robot to drive a circle fascinating. It reminded me of a book that I read 27 years ago called "Fuzzy Logic" by Daniel McNeill and Paul Freiberger. It was a concept of dealing with problems, not in a binary On Off fashion but more in the line of thinking of degrees of On or degrees of Off. The idea was invented in the US by Lotfi Zadeh but more commercially developed by the Japanese. I believe that your approach to solving the circle drive problem falls in the Fuzzy Logic category.

John