Most diodes I've come across have the part number printed on the body.
This small glass diode however, uses color-band coding instead.
The idea is probably that the small dimensions on a cylindrical surface would not create clear enough numbers, especially when mass-produced at high speed.
Painting color bands is much easier to manufacture, and instantly readable.
This diode value had me stumped for a long time, as I was thinking in terms of resistor coding (digit, digit, multiplier, tolerance), and as it tested as a diode, not a resistor, the calculated value of 410000 (410K) made no sense, and thought the greyish-silvery 4th band was 5% tolerance.
While recently looking at the original photo I took, I again wrote the 4 values down on paper - then it struck me!
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The diode bands are read "as is", digits only, to signify part number 4148.
Band1 is thicker than the rest.
(But not as thick as he who was staring uncomprehendingly at the obvious).
If forum admin / moderators are OK with this, this thread could be an "open" thread for "not commonly known to everybody" or "unusual / handy tips" relating to electronics, electrical, workshop hints...?
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This small glass diode however, uses color-band coding instead.
The idea is probably that the small dimensions on a cylindrical surface would not create clear enough numbers, especially when mass-produced at high speed.
Painting color bands is much easier to manufacture, and instantly readable.
This diode value had me stumped for a long time, as I was thinking in terms of resistor coding (digit, digit, multiplier, tolerance), and as it tested as a diode, not a resistor, the calculated value of 410000 (410K) made no sense, and thought the greyish-silvery 4th band was 5% tolerance.
While recently looking at the original photo I took, I again wrote the 4 values down on paper - then it struck me!
| Band: | Color: | Value: | Thought: | Actual: |
|---|---|---|---|---|
| 1 | Yel | 4 | 4 | 4 |
| 2 | Bro | 1 | 1 | 1 |
| 3 | Yel | 4 | x10E4 | 4 |
| 4 | Gry | 8 | 5% | 8 |
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The diode bands are read "as is", digits only, to signify part number 4148.
Band1 is thicker than the rest.
(But not as thick as he who was staring uncomprehendingly at the obvious).
If forum admin / moderators are OK with this, this thread could be an "open" thread for "not commonly known to everybody" or "unusual / handy tips" relating to electronics, electrical, workshop hints...?
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