This is a quick reference of all Burr type distributions with their CDF, PDF and PPF functions. I found no complete reference with both of these on the internet, but had to go through papers and multiple websites to compile this.
I have calculated the PDF and PPF functions using FriCAS and Maxima where needed.
Hopefully I didn’t made a mistake typing those in. If you see something wrong or would like to add something drop me a line jan@jadelsbach.de.
Repairing another Gossen Pantam Konstanter T2 33 015
This is a follow-up to the other two I repaired a while back part 1 and part 2.
So I got another one of those Gossen Pantam Konstanter T2 33 015 lab power supplies from the 70s with Germanium transistors and selenium rectifiers. Similiarly to the ones I got before the capacitors had leaked quite a bit and needed replacement. Furthermore the drive transistor was broken, so I replaced that one as well.
Burg Neudahn December 2024
All pictures taken either with my Sony SLT-a77 with a Sony DT 18-55mm F3.5-5.6 SAM and a Tamron SP AF 70-300 F/4-5.6 Di VC USD objective.
Burg Gräfenstein November 2024
All pictures taken either with my Sony SLT-a77 with a Sony DT 18-55mm F3.5-5.6 SAM and a Tamron SP AF 70-300 F/4-5.6 Di VC USD objective or with my old Canon EOS 20D with a Canon EF 4,0-5,6/35-80 III.
Pictures taken with my Sony Pictures taken with my Canon
Repairing a BOSCH 12A 6V/12V Battery Charger
This is one of my old battery chargers, the selenium rectifier went bad and started to internally short out.
Replacing selenium rectifiers with silicon diodes is not recommended on non-short protected battery chargers, as the selenium rectifiers have an internal resistance that acts as a current limit on short circuits. In this case the secondary side is proteced and I’ll try not to short it out.
I replaced the selenium rectifier with a beefy bridge rectifier and also made a small heatsink out of sheet metal to get the temperature of it a little down into nominal operating range.
Repairing 3x 12V Stabilized Power Supplies
Voltcraft 13.8V 2/3A Regulated Power Supply I recently got this from eBay. The previous owner added an optocoupler that interrupts the current to the control chip, such that the supply can be soft- turned off and on remotely.
I removed this circuitry and restored the supply into its original order, furthermore I replaced the two capacitors since it looked like that unit had quite a runtime over the years.
Furthermore the voltage adjustment potentiometer fall apart, so I replaced that one, too.
Repairing S1-94 (С1-94) Oscilloscopes
I got two old Soviet S1-94 (С1-94) Oscilloscopes which I use occasionally. However I noticed that they had increasing problems generating the high-voltage for the cathode ray tube (took a very long time to start up), as well as general jitter. I deduced that this is the most likely result of old soviet capacitors.
Warning the high-voltage supply will retain a charge for an unspecified amount of time after powering the unit off. Recapping #1 This one was partially recapped by the previous owner. I also recapped some definitely broken capacitors beforehand but decided to also recap the rest now.
Loewe Opta R142 Repair
Recapping the Radio The capacitors in the radio did not look that good and showed signs of long use. Given the paint came off the On/Off and UKW buttons I can assume that this radio was in daily operations for maybe even decades.
The replaced capacitors, as you can see the ones around the power supply look kinda bloated and have skid marks on them from the heat of the main supply transformer. Was definitely time to replace them:
13.4V / 5A Linear Power Supply
I got someone’s old 13.4V 5A power supply project off a batch of electronics stuff from eBay and figured to give it a revamp. This is the unit as I got it:
Basically a LM7812 driving two TESLA KU607VC TO-3 transistors. The LM7812 is offset by a zener diode to account for the voltage drop of the KU607VC transistors.
I did a total overhaul of the circuit I switched out some components (especially the capacitors), added a current meter and put it in a proper enclosure. I also added a primary fuse (previous thing was missing one) and added in a polyfuse on the secondary side.
VISOMAT light barrier
I recently got this ancient Visomat light barrier made in eastern Germany (GDR/DDR) consisting of a transmitter and a receiver. By comparison to modern light barriers, this is indeed a visible light barrier, the transmitter contains a 6V/15W tungsten bulb. So I figured to build a controller for it and get it back to work.
Transmitter and Receiver The receiver contains a phototransistor, due to the optics on the receiver there is still a fairly decently fine line of sight, not the full entry lens needs to get covered to register a trigger only the center most part. I wanted to keep the 6V bulb for one of my microscopes which uses this type however since I wanted to run everything off 12V anyhow I put a warm-white LED into it. On the receiver (which I haven’t made a photo off, but is just a 5k resistor and a phototransistor inside) I just attached a new cable.