git @ Cat's Eye Technologies Electronics-Projects / 2978183
Embed images as raw files, attempt to fix anchor links. Chris Pressey 4 years ago
3 changed file(s) with 12 addition(s) and 21 deletion(s). Raw diff Collapse all Expand all
1717 1Q0L
1818 ----
1919
20 <div id="figure1">
21
22 ![The 'Kitsilano' Oscillator
23 Circuit](1Q0L_oscillator.png "Figure 1. A single-transistor (and apparently inductor-less) oscillator.")
20 ![The 'Kitsilano' Oscillator Circuit](1Q0L_oscillator.png?raw=true)
2421
2522 Figure 1. A single-transistor (and apparently inductor-less) oscillator.
26 (From [Sessions 1975](#1)).
27
28 </div>
23 (From [Sessions 1975](#references)).
2924
3025 The notion of a single-transistor oscillator, built without an inductor,
3126 tantalized me for a while after I came across what looked like such a
3227 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
28 public library ([Sessions 1975](#references)). It is shown in Figure 1. It clearly
3429 contains only one transistor and no coils, and the caption claims that
3530 the tone it produces, though not loud, is adequate for keying (that is,
3631 Morse code) practice. Further, the circuit is organized in a way that
5752 The Design of the Kitsilano Oscillator
5853 --------------------------------------
5954
60 <div id="figure2">
55 ![The 'Kitsilano' Oscillator Circuit](kitsilano.png?raw=true)
6156
62 ![The 'Kitsilano' Oscillator
63 Circuit](kitsilano.png "Figure 2. The 'Kitsilano' Oscillator Circuit.")
6457 Figure 2. The 'Kitsilano' Oscillator Circuit.
65
66 </div>
6758
6859 Having given up on a single-transistor, inductorless oscillator, and
6960 discovering in other library books several single-transistor,
7667 which triggers the other pair when it has discharged. Another design
7768 involves only a single capacitor, but two transistors of complimentary
7869 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).
8071
8172 Well, what I wanted was an oscillator built from two transistors of the
8273 *same* type, but incorporating only *one* capacitor. This effort
8980 output through an RC circuit, and the other inverter is used to
9081 stabilize the feedback and "square off" the output. Circuits
9182 incorporating this oscillator design can also be found in
92 Mims^[\[2\]](#1)^.
83 [Mims 2003](#references).
9384
9485 (In fact, it's not required that such an oscillator be constructed from
9586 CMOS gates. [This figure](2NOR_oscillator.png) shows a circuit along the
55
66 The LM386 audio amplifier IC, that is...
77
8 ![Photo of LED-386](doc/led386_photo.jpg)
8 ![Photo of LED-386](doc/led386_photo.jpg?raw=true)
99
10 ![Schematic of LED-386](doc/led386.png)
10 ![Schematic of LED-386](doc/led386.png?raw=true)
1111
12 [Download the .dia file of the schematic](https://github.com/catseye/Electronics-Projects/blob/master/led386/doc/led386.dia?raw=true).
12 [Download the .dia file of the schematic](doc/led386.dia?raw=true).
22
33 *January 10 2003*
44
5 ![Photo of Mildred](doc/mildred_photo.jpg)
5 ![Photo of Mildred](doc/mildred_photo.jpg?raw=true)
66
77 Mildred is a homebrew computer. Since it is continually changing, this
88 document describes both the current state of Mildred, and what it would
5656 ### Reset Mechanism
5757
5858 Currently, Mildred must be manually reset after power-on by the reset
59 switch (which simply grounds the /RST line of the Z80.) Ideally, a
59 switch (which simply grounds the `/RST` line of the Z80.) Ideally, a
6060 DS1223 reset circuit would be used as to consume neglible real estate on
6161 the board.
6262
110110 Block Diagram
111111 -------------
112112
113 ![Block Diagram of Mildred](doc/mildred.png)
113 ![Block Diagram of Mildred](doc/mildred.png?raw=true)
114114
115115 Testing
116116 -------