I have this older soviet microscopy cold light/fibre optics source “ОБ” for MБС-10 microscopes. In order to increase the life of the 12V 75W halogen lamp inside I wanted a slow start circuit that first limits the current through the bulb such that the latter can preheat a bit before it goes over to full power. To accomplish this I built a simple NE555 timer circuit that switches a relay that bridges out a 2R7 power resistor that limits the current through the bulb.
230V Phase Angle Control Dimmer
A fairly simple phase angle control dimmer using a triac, diac, resistor, potentiometer and a capacitor. For noise suppression I added an inductor and a filter capacitor.
Arduino Traffic Light Controller
Fairly simple traffic light controller I built the other day. It consists of 5x relays switched using a ULN2803 darlington array with free wheeling diodes from an Arduino. Two digital inputs are also available to hook buttons up. 12V/DC power is supplied using a 230V/AC PCB SMPS module.
Not too much to say about it really.
Teufelsburg (Saarland)
All pictures taken with my Sony SLT-a77 with a Sony DT 18-55mm F3.5-5.6 SAM and Tamron SP AF 70-300 F/4-5.6 Di VC USD objective.
Château du Falkenstein
All pictures taken with my Sony SLT-a77 with a Minolta AF 28-100mm F3.5-F5.6, Minolta AF 50mm F1.7 and Tamron SP AF 70-300 F/4-5.6 Di VC USD.
Unfortunately we got extreme sun on that day, so it was always a game of finding the right exposure compensation.
Dresden May 2023
All pictures taken with my Sony SLT-a77 with a Minolta AF 28-100mm F3.5-F5.6 and Sony DT 18-55mm F3.5-5.6 SAM objective.
Fürstenzug Dresden Zwinger Dresden Zwinger was partially closed for construction at the time of my visit.
Architecture View Japanisches Palais
Quick Repair: Tempophot
I got this old camera photometer a while back and it wasn’t working, so I figured let’s see what’s wrong with it. Turns out the photocoll just wasn’t making good contact, I rotated it slightly ~45° and the meter started working again.
The fotocell is dated 26. March 1935.
Links Tempophot - Antique and Vintage Cameras Tempophot T-4
Zoo Saarbrücken May 2023
All pictures taken with my Sony SLT-a77 with a Tamron SP AF 70-300 F/4-5.6 Di VC USD objective.
Corsac Fox Kangaroos (Or wallaby? Map and website of the Zoo are fairly non-descriptive)
Meerkats Giraffe Common Eland Antelope Storks Red Pandas Peafowls Chicken Jaguar
7W Linear LED Driver
Built another linear dimmable LED driver to retrofit into my microscopy equiptment. This one is for retrofitting my LOMO ОИ-35. It’s a fairly standard current reguator circuit working on unregulated DC. I used a 2N3054 transistor as the main series pass transistor for a change.
Hund FLQ75 Repairs
Circuitry Overview The circuit is super simple, there is a motor run capacitor for the AC fan which is connected to a separate tap on the transformer and insulated from the rest of the circuitry. A small triac dimmer on the secondary 12V AC side using a MAC223 triac and another 3 pin TO-92 device which I think is either another triac or a SCR two film capacitors and a couple potentiometers. Haven’t bothered to reverse engineer the exact circuit, as the PCB can’t be removed without desoldering all the wires which I did not want to bother with at this time.