As mentioned in the MBS-10 (МБС-10) post the standard LOMO power supply is not safe by modern standards. It uses a non-earthed metallic case and does not have fuses. I recently got this supply together with my new LOMO R15 (ЛОМО Р15) where the prior owner cut off the standard europlug and added a Schutzkontaktstecker using screw terminals. It is as safe as it looks:
While disassembling it I also noticed that the shrinking tube was improperly sized, exposing live 230V terminals:
LOMO R15 (ЛОМО Р15)
I recently got this LOMO R15 (ЛОМО Р15) as I wasn’t satisfied with the accessories my Hertel & Reuss microscopes have and the virtual non-availability of further accessories for those on eBay. So I decided to go with a microscope I can get more easily upgrades for.
As visible from my earlier posts regarding this:
LOMO ST-12 (ЛОМО СТ-12) Repair Cleaning a LOMO R15 (ЛОМО Р15) Frame LOMO OI-35 (ЛОМО ОИ-35) Repair There was some cleaning and mechanical maintenance required, to get it back into operation.
LOMO OI-35 (ЛОМО ОИ-35) Repair
I got this together with my new LOMO R15 (ЛОМО Р15), the iris diaphragm inside was broken, so here a quick note on how I repaired it.
I started with dissembling everything, in order to get the diaphragm out the two levers need to be unscrewed as well as a small set screw on the bottom needs to be removed. I also disassembled the mirror part for cleaning.
Analog Threshold Relay
This is part of my readout electronics system.
This is one of the oldest modules I built that I haven’t desoldered so far. It is an analog threshold relay with voltage reference and amplification.
There is a 10V reference voltage feeding into the 10-turn potentiometer on the front panel, this selects the threshold voltage. A lever switch selects whether the input signal is amplified by x10 or just passed through to the comparator. The comparator (LM358) itself is a window comparator where another lever switch selects whether to take the trigger signal from the under- or over voltage outputs. The selected output then triggers a relay. The LED on the front panel is dual-color (R-G), where red indicates that the unit has triggered and green indicates that the unit is powered and ready.
Cleaning a LOMO R15 (ЛОМО Р15) Frame
So as mentioned in the preceding article about my LOMO ST-12 (ЛОМО СТ-12) Repair I got a new LOMO microscope! A LOMO R15 (ЛОМО Р15) to be precise, in this post I briefly go over cleaning the main frame of it, as mine was dirty and the mechanical parts were hard to operate.
The green stuff is a grease spillage, where the grease liquefied by heating up and spilled all over the microscope. This indicates that the microscope either sat somewhere hot or on the outside in the sun for a while.
LOMO ST-12 (ЛОМО СТ-12) Repair
So I recently got a LOMO R-15 (ЛОМО Р-15) microscope, that badly needs some cleaning and servicing. So let’s start with the XY stage which is a LOMO ST-12.
As can be seen from this image it is slightly rusty and really dirty.
I basically started by disassembling it and cleaning all parts in the process. There was quite a lot of excess grease and oil on it implying that someone had a go with this before.
Universal Temperature Controller
I got one of these cheap “REX C100” temperature controllers from Amazon a while back. So I figured I’ll make it usable by building a desk temperature controller with it.
Modifying the Controller By default when you buy cheap temperature controllers like this it’s essentially Russian roulette on whether you get one with a SSR driver or a relay output. I happened to get one with a SSR driver, but need a relay for this. Fortunately it’s the same PCB as the relay version and the latter uses a fairly standard footprint. So I just looked through my box with 12V relays and found one that fits.
Microscopy Insights #2: Stereomicroscopy of an Aglais io
Found this dead Tagpfauenauge aka European peacock (Aglais io) on the attic. Looks like some spiders got to it, but interesting to look at under the microscope nonetheless.
Click to enlarge Pictures taken with a Sony SLT-a37 on my MBS-10 (МБС-10) with the МФУ tube.
Monitoring CISCO Catalyst System Utilization with collectd
Someone recently asked me how to monitor the CPU and memory utilization, as well as the peak bandwidth of CISCO Catalyst switches, as I collect those metrics for mine using collectd with the SNMP plugin.
Please note that any data definitions in i.e. your types.db need to be synchronized to all other machines that receive the data if you are pushing the data onto a central server.
Total Bandwidth
700mA Linear LED Driver
I built this small linear LED regulator a while back. Initially I built it to upgrade my ОИ-19 microscope illuminator to LED, but I decided to use the remaining light bulbs until they break before I start upgrading it to LED.
I used a couple of soviet potentiometers to go with the theme (СП4-1), it’s a simple standard linear current regulator based off two transistors. The gate current can be adjusted with the internal potentiometer, which allows programming the maximum LED current (up to 800mA). The main transistor (TIP41C) had it’s legs break off, when I desoldered it from somewhere (was probably bent for a heat sink) so instead of throwing it away I just soldered some wires onto it.