| 17 | 17 |
1Q0L
|
| 18 | 18 |
----
|
| 19 | 19 |
|
| 20 | |
<div id="figure1">
|
| 21 | |
|
| 22 | |
|
|
20 |
|
| 24 | 21 |
|
| 25 | 22 |
Figure 1. A single-transistor (and apparently inductor-less) oscillator.
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| 26 | |
(From [Sessions 1975](#1)).
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| 27 | |
|
| 28 | |
</div>
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|
23 |
(From [Sessions 1975](#references)).
|
| 29 | 24 |
|
| 30 | 25 |
The notion of a single-transistor oscillator, built without an inductor,
|
| 31 | 26 |
tantalized me for a while after I came across what looked like such a
|
| 32 | 27 |
circuit in a book of somewhat older circuits that I checked out from the
|
| 33 | |
public library^[\[1\]](#1)^. It is shown in Figure 1. It clearly
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|
28 |
public library ([Sessions 1975](#references)). It is shown in Figure 1. It clearly
|
| 34 | 29 |
contains only one transistor and no coils, and the caption claims that
|
| 35 | 30 |
the tone it produces, though not loud, is adequate for keying (that is,
|
| 36 | 31 |
Morse code) practice. Further, the circuit is organized in a way that
|
|
| 57 | 52 |
The Design of the Kitsilano Oscillator
|
| 58 | 53 |
--------------------------------------
|
| 59 | 54 |
|
| 60 | |
<div id="figure2">
|
|
55 |
|
| 61 | 56 |
|
| 62 | |
|
| 64 | 57 |
Figure 2. The 'Kitsilano' Oscillator Circuit.
|
| 65 | |
|
| 66 | |
</div>
|
| 67 | 58 |
|
| 68 | 59 |
Having given up on a single-transistor, inductorless oscillator, and
|
| 69 | 60 |
discovering in other library books several single-transistor,
|
|
| 76 | 67 |
which triggers the other pair when it has discharged. Another design
|
| 77 | 68 |
involves only a single capacitor, but two transistors of complimentary
|
| 78 | 69 |
type (NPN and PNP.) Many circuits based on both of these oscillator
|
| 79 | |
designs can be found in Mims^[\[2\]](#1)^.
|
|
70 |
designs can be found in [Mims 2003](#references).
|
| 80 | 71 |
|
| 81 | 72 |
Well, what I wanted was an oscillator built from two transistors of the
|
| 82 | 73 |
*same* type, but incorporating only *one* capacitor. This effort
|
|
| 89 | 80 |
output through an RC circuit, and the other inverter is used to
|
| 90 | 81 |
stabilize the feedback and "square off" the output. Circuits
|
| 91 | 82 |
incorporating this oscillator design can also be found in
|
| 92 | |
Mims^[\[2\]](#1)^.
|
|
83 |
[Mims 2003](#references).
|
| 93 | 84 |
|
| 94 | 85 |
(In fact, it's not required that such an oscillator be constructed from
|
| 95 | 86 |
CMOS gates. [This figure](2NOR_oscillator.png) shows a circuit along the
|