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I think this page is too specific. There are other types of relaxation oscillators---your heart and circadian rythm, for example. I think this page should be changed to focus on the concept of how an accumulating signal and thershold for release can be used to construct a relaxation oscillator. neffk ( talk) 20:14, 4 September 2008 (UTC)
We need a diagram of the "classic" relaxation oscillator. Here is one in ASCII-Art, which may help. The symbols are poorly drawn, especially the neon bulb. Values are approximate; T ~ RC = 1 second (here) See also Pearson-Anson_effect.
|---------| Resistor, 100k | 200 V +|---------\/\/\/--------+-----------| | DC | | | | supply | capacitor + ------ ( o ) neon bulb | | 10uF ------ ( o ) | | | | | -|-----------------------+-----------| |---------|
A simple relaxation oscillator may also be built from a 555 (wired as an inverting schmitt-trigger), and a single resistor/capacitor.
Wiring is:
First, wire up an inverting schmitt-trigger from the 555. Pin 1 = Ground Pin 8 = Positive Pins 4,5,7 are left unconnected Pin 3 = Output. Pins 2,6 are connected together. Then, connect the RC between pin 3 and ground, with pins 2,6 connected to the junction: PIN3 ----\/\/\/----PIN2,6----||-----GND
Note: The "normal" 555 astable configuration (using pins 2,6,7, and having 2 resistors and a capacitor) is not a relaxation oscillator: it is more complex.
This article is made far less useful because all three resistors in the circuit are given identical values, R. Noodle snacks ( talk) 11:35, 16 May 2009 (UTC)
The article states:
and
However, as long as VDD and VSS are symmetrical compared to ground, the op-amp oscillator's capacitor will charge and discharge at the same rate and the output will be a triangle wave.
Either the op-amp oscillator is not a relaxation oscillator or the relaxation oscillator needs to be redefined. Rsduhamel ( talk) 22:06, 29 December 2009 (UTC)
I added the following short section just now (with illustration):
A blocking oscillator using the inductive properties of a pulse transformer to generate square waves by driving the transformer into saturation, which then cuts the transformer supply current until the transformer unloads and desaturates, which then triggers another pulse of supply current, generally using a single transistor as the switching element.
Note that I'm far from pedagogically sound on the theory here, so edits are encouraged. The text I wrote was intended to be (barely) enough to direct the reader to the better explanation at the target link. — MaxEnt 18:40, 31 May 2020 (UTC)
![]() | This article is rated Start-class on Wikipedia's
content assessment scale. It is of interest to the following WikiProjects: | ||||||||||
|
I think this page is too specific. There are other types of relaxation oscillators---your heart and circadian rythm, for example. I think this page should be changed to focus on the concept of how an accumulating signal and thershold for release can be used to construct a relaxation oscillator. neffk ( talk) 20:14, 4 September 2008 (UTC)
We need a diagram of the "classic" relaxation oscillator. Here is one in ASCII-Art, which may help. The symbols are poorly drawn, especially the neon bulb. Values are approximate; T ~ RC = 1 second (here) See also Pearson-Anson_effect.
|---------| Resistor, 100k | 200 V +|---------\/\/\/--------+-----------| | DC | | | | supply | capacitor + ------ ( o ) neon bulb | | 10uF ------ ( o ) | | | | | -|-----------------------+-----------| |---------|
A simple relaxation oscillator may also be built from a 555 (wired as an inverting schmitt-trigger), and a single resistor/capacitor.
Wiring is:
First, wire up an inverting schmitt-trigger from the 555. Pin 1 = Ground Pin 8 = Positive Pins 4,5,7 are left unconnected Pin 3 = Output. Pins 2,6 are connected together. Then, connect the RC between pin 3 and ground, with pins 2,6 connected to the junction: PIN3 ----\/\/\/----PIN2,6----||-----GND
Note: The "normal" 555 astable configuration (using pins 2,6,7, and having 2 resistors and a capacitor) is not a relaxation oscillator: it is more complex.
This article is made far less useful because all three resistors in the circuit are given identical values, R. Noodle snacks ( talk) 11:35, 16 May 2009 (UTC)
The article states:
and
However, as long as VDD and VSS are symmetrical compared to ground, the op-amp oscillator's capacitor will charge and discharge at the same rate and the output will be a triangle wave.
Either the op-amp oscillator is not a relaxation oscillator or the relaxation oscillator needs to be redefined. Rsduhamel ( talk) 22:06, 29 December 2009 (UTC)
I added the following short section just now (with illustration):
A blocking oscillator using the inductive properties of a pulse transformer to generate square waves by driving the transformer into saturation, which then cuts the transformer supply current until the transformer unloads and desaturates, which then triggers another pulse of supply current, generally using a single transistor as the switching element.
Note that I'm far from pedagogically sound on the theory here, so edits are encouraged. The text I wrote was intended to be (barely) enough to direct the reader to the better explanation at the target link. — MaxEnt 18:40, 31 May 2020 (UTC)