Saturday, August 15, 2026
Ωκεανός - Ναντια Διολιντζή Lyrics, Γιωργος Τσακίρης music, Ocean - Nandia Diolingi, George Chakiris, elements of the song
Thursday, August 13, 2026
A simple MOSFET power amplifier with just a 12V battery, a potentiometer and resistor for bias, an input coupling capacitor and no output transformer
At your risk. It may blow your spekaer if a protective fuse is not connected in series etc.
Please see previous post on Pleiades K951 amplfier with speaker connected directly to the drain of the MOSFET.
Update on Pleiades K951single MOSFET zero feedback single ended power amplifier
At your risk.
Today the bifilar 1:1 output transformer was disconnected from drain and connected to the source. This was done fairly quickly as all connections are done with Wago snap terminal connectors.
Source follwer configuration worked with change with readjustment of bias from the 50K potentiometer in series with 47K but sensitivity was low as there is no voltage gain.
Signal path:
CD - SONY CD Walkman - Pleiades K951 as source follwer - Marantz Imperial 5C
So power suppling the speaker was low.
The amplifier was remodified to drain follower.
Then the output transformer was removed and the AKAI SR H-44 speaker connected directly to drain instead of a load resistor. This should not blow the speaker if drain currect (which now passes through the voice coil) is kept by suitable bias to up to say 300mA. It worked and sounded nice, but less loud than when using the output transformer due to loss of efficiency.
Betasilk or Betaplast etc
At your risk. This is not a medical or dermatologist advice. Betadine cream is not suitable for persons with thyroid problem.
Combining 2 products together to create a new product.
Hansaplast with Betadine cream.
Hansaplast moistened with Betadine cream applied on skin spots may vanish the spot if applied overnight(s) or during the day.
Betadine cream softens the spot until it breaks, it disinfects and the Hansaplast tisue absorbs.
Thsi idea comes from adapting my dermatolosgist Yiannis Peros' advice when I had a serious skin infection.
Tuesday, August 11, 2026
Merino Wool t-shirts
At your risk.
One of the best thing bought this year. Black long sleeved.
They are 3 times more expensive than cotton but they last at least 3 times more.
Minerva brand.
They keep you warm in the winter, dry on both seasons.
When the is heavy air conditioning in the summer, you are saved as you are dry before entering the air conditioned environment and you don't feel cold.
Dryness in the key.
And they feel compatible with one's skin.
Monday, August 10, 2026
Πολυκυκλωματιστής 501-Β, electronic construction game Polykyklomatic 501-B
At your risk.
Educational Electronics Laboratory.
It is made in a box similar to Monopoly.
70's, 80's game.
Springs are used to secure contact to electronic components.
The amplifier does not have an output transformer.
The germanium transistor is directly coupled to the loudspeaker.
Everything operated on a 9V battery.
C1 100nF
C2 2nF
C3 220uF 10V
C4 1.8nF?
C5 40uF 16V
speaker Sanyo PAN Q GH 8ohm 0.3W
potentiometer: 8.8KOhm
lamp: 14ohm when cold
3 Germanium Transistors, using the diode setting of a digital multimeter they measure:
T1, 9H: BE 0.13V, BC 0.123V
T2, 9o: BE 0.4V, BC 0.142V
T3 7c: BE 0.125V, BC 0.111V
By examining the schematics and internal connections below the springs, the amplifier output stage seems to be an emitter follower capacitor coupled (C3) to the speaker
I fondly remember this game. It gave the opportunity to make my first amplifier. I did not know whether it worked. I did not know how to test it. All I could hear was a click in the small speaker and I thought I had done something wrong.
It all came to life when the radio AM tuner from the bigger game 1002 (102 constructions) was connected and radio could be heard around the room with good quality.