Category: Blog

555 Contest Entry

This is my entry for the 555 contest. I didn’t have much time to make something so the entry isn’t much.

This design is a fan controller. The base of it is a simple pwm circuit with the 555 timer. The problem with fan’s is that they don’t start at low voltages. So I added a capacitor (C2) to give it a little voltage boost at the startup.



The circuit can also be easily adjusted to have a soft start. This can be useful when driving led’s etc. This way the light is not instantly bright.


“100W Temperature Controlled Soldering Pot” Review

I bought a “100W Temperature Controlled Soldering Pot” and decided to write a review about it.

KLT-360 Solder Pot Titanium Alloy Soldering Melting Tin 38mm 100W

The box doesn’t contain much. Only the soldering pot and a chinese manual.

Take it apart:

The next thing to do is to open it up and see if it is safe enough to plug in to the mains.

After cutting the too long wires down to size I decided to take a closer look at the pcb. Then I saw that it was not temperature controlled like the dx site claims. The power to the heater is controlled, but there is no feedback. I made a circuit of it to proof it.

First I have made some good pictures of the pcb:

Then I placed the 2 pictures on top of each other and made the top one transparent:

Now it is easy to derive a circuit diagram from this.

There is not enough space between the pcb and the enclosure, especially because it is made of metal, luckily it is grounded. The wires are cut too long.
The pcb looks like its soldered very good, I didn’t expect this with something this cheap.

Powering It Up:

Tinning Some Wire And PCB:

Temperature Accuracy Test:

I’ve put the thermocouple from my multimeter in it. In the lowest range of the soldering pot it should be arround 200°C and I measure 279°C. If it was really temperature controlled like dx claims then the difference would be too big. Because the power is controlled this could be expected.


It is a pity that it is not really temperature controlled, but for the money you pay for it, it was to be expected. But this doesn’t really makes it work bad. If you use flux or soldering grease then the wires tin very easy.
So I think it is a good buy :). But keep in mind you still need to buy/have enough solder to put in it. You can use normal solder, but then its going to smoke a lot at first.

Switch Clock

ON5DRE used my Switch Clock schematics to create his own switch clock.

More pictures: Link

Looks great ON5DRE!

The Amp Hour

My site got mentioned on the amp hour :).

Christmas presents

I got my Christmas presents today :).

What I got:
IC extractor
SMD test tweezers
figure sawing aid

Starting a new Blog

Today I switched to WordPress for my new blog. All the new entry’s will be in English. The old imported entry’s stay in Dutch.