Other projects

I use an autoradio on my boat and this radio has a subwoofer output. The problem is it needs an active sub-woofer and I had a nice small passive subwoofer (140W) from an old stereo set I did not use anymore. Amplifiers are not “my thing” and I was busy with work so I needed … Read more

I had this Velleman but after 3 years daily use it kinda fell apart and the lenses became to scratched   I then bought this from bangood.    Those two merged gave me the comfort of the first (easy flipping it up and comfort) and the nice optical qualities of the second. The lenses are … Read more

I bought a 10A 43kilo’s isolation transformer. I had a small one that I fried. Circuits Online member Ginny found this beast at Baco. She brought it per boat to a city nearby me and I collected it there.   I made an operation panel for it. The big red switch is there to decouple … Read more

After seeing the Stick-vice on you tube I wanted one. At first I thought is was a strange rather useless thing but it turned out to be very handy. You can use it to hold a pcb level under a microscope, use it on both sides, work while resting your wrists/hands on the bench for … Read more

We have a “Kruimeldief”, a battery-powered vacuum cleaner. It was previously unusable because the batteries would no longer feed it. The original adapter was a 15V AC adapter and in the kruimeldief there was a diode. It has a battery pack with 6 C-size nicd cells. Two cells were dead. I changed the two cells for … Read more

Working on my 3D printer gave me the idea to make this over the top 3rd hand solder and repair “thing” The aluminum profiles in my junk box begged me to use them for something. They are the bigger brother from the once used in my printer. I wanted a solution for several ” problems” … Read more

If you have like me, a nice collection of multi-meters, you probably also have a lot of probes. I like testleads that have bananaplugs instead of permanent probes. This way I can use them with probes, crocodile clips etc. I kept them in a drawer of my desk in a box. I like sharp probes … Read more

I use an isolation transformer and a variac combined with a light-bulb when I repair mains powered instruments. But that is not close enough if things go wrong. You know, the kinda problems that communicate with smoke…. This cabinet houses also a reset-able 15A fuse. Not really needed because the variac/isolation transformer unit is fused, the … Read more

This is an adapter that makes a 24/7 battery charger from a normal 14V power-supply. The original design is published in Funk-amateur, a German magazine. That is a very clever design and very simple, some leds, resistors and 2 relais. I made some changes to the design. I added my desulfator  and two comparators.  Because the … Read more

  It uses two resistive heaters in serie. The temp is controlled by a PID controller. On top you see a fan. This cools the oven if needed so I can cool it faster. It scuckes cool air in through holes in the bottom, via the room between inner and outer cabinet to the top. … Read more

I mounted a few banana plugs to a pair of Peiker microphone “goose necks”  This way I can mount crock clips to them. They are mounted to a aluminum L-profile. They  are very precise and stable. It is very easy to position them so it can hold two wires against each other.

Smoking solder is not a very healthy addiction 🙂  The fumes contain stuff that is not good for your health. Especially the solder that contains lead.  How bad it is, I have no clue. I read that lead in solder is only harmful above a temp of 500C. But it does irritate my nose/lungs. I … Read more

For rewinding transformers or coils I made this thing from junkbox parts. The open wheel and brake is from an old sewing machine . The aluminum from an old grinding machine. The other parts are spares from my Unimat mill.  This way I can mount every accessory of my lathe to it. After the pictures … Read more

I have a Pace MBT-250 including the tweezers but without tips. These tips are very expensive. Today I needed to remove a smd IC from a Fluke 725 process calibrator. It was exposed to 230Vac on the 30VDC input. Some traces were burned and someone had replaced the 4053. Measurements showed there were contact problems. … Read more

  This is a 2x10W amplifier made from a kit we sold at the ham-fest in rosmalen this year. I wanted a small amp for my laptop and this little amp was ideal for my use. It had to be transportable but I do not need battery power. Allthough that would not be a problem. … Read more

I use now and then a microcontroller. Because it is easy and there is a lot of info I use an Arduino. But as easy it is to use, as hard is it to use only the Atmel after programming in a project. The pin layout and numbreing is rather cryptic. So I bought a … Read more

Our house has a cellar and there is some strange water resevoir in there. No clue what its use is but if groundwater goes up (I live nearby a big river) this resevoir fills with water and when full, it fills the cellar so I use a small pump to empty it. I used a … Read more

The problem of a breadboard is that they are light so if you have some coax , psu lines and probes connected I most times end up witth the breadboard dropping from the table and hanging to some cables. I added a display and made a levelshifter so I can use it for the TI … Read more

I wanted a hotair station for   big things like RF shielding. So I went to the garage, took a piece of sheetmetal, my bodywork tools and fired up my smallest autogene welder. The result is the thing above this text. The tube at the end fits snug  into copper tubing so I can make … Read more

    This circuit is a often used circuit for nixie tubes. I wondered how it held up to this one: http://www.pa4tim.nl/?p=4364 This schematic is easy to build, no problem getting it to work but the Voltage regulation sucks. It changes under different ,loads. I used a 1nF capacitor for C1 and a BFY90 as transistor. … Read more

  I needed a 12 to 24V boost converter. Most times I use a special smps driver/controller. Once used a 555 but  I was in an experimental mood. I found several schematics that all seems to be just copies from each other. It uses two opamps (lm324 or two separate opamps)  and a powertransistor, you … Read more

While restoring a Fender twinreverb I needed something to use instead of speakers. The amplifier is capable of delivering 135W into 4 Ohm. But it is no problem to use a load with more resistance . I was in doubt between making a dummy-speaker or a resistive one so I measured the impedance of the speakers … Read more

Wat ideetjes om te detecteren dat de stroom is uitgevallen. Zodat je weet dat je wekker mogelijk de volgende morgen niet meer klopt, of natuurlijk belangrijker, de ovens van volt en tijdstandaards staan af te koelen. Het zijn geen gebouwde ontwerpen maar gewoon ideetjes. De waarden van gebruikte onderdelen is dus willekeurig. Bij de schakeling … Read more

Dit is een Audiotrap met tegenkoppeling op basis van een triode/pentode ECL86. De voeding is wat overbemeten en voorzien van twee bussen waar 250V op staat en 2 bussen waar 6,3V gloeispanning op staat. Op advies van Fritjof Sterrenburg heb ik deze gebouwd. Nu kan ik ontvangers enzo bouwen zonder steeds weer een voeding en … Read more

Dit was een gesneuvelde logitech webcam. Ik heb het ding in een kunstof huisje gebouwd. Deze was motorisch te zoomen. Door nu de lens met de hand in en uit te schroeven kan ik tot op een paar cm scherpstellen.  er zijn voor dit type geen Windows7 drivers meer maar zoals gewoonlijk is het bij … Read more

Omdat ik altijd ruzie had met mijn desoldeerpompje heb ik dat maar eens aangepakt.  Je moet het met een hand op zijn plaats houden, met de andere solderen en als je de knop indrukt springt het ding net weg. Ik heb met kneedbaar metaal van Bison de knop en zuiger ingang dichtgestopt. Een messing pijpje … Read more