| Forum Home | ||||
| PC World Chat | ||||
| Thread ID: 58598 | 2005-06-06 00:08:00 | Oscillator | Dannz (1668) | PC World Chat |
| Post ID | Timestamp | Content | User | ||
| 361495 | 2005-06-06 00:08:00 | I was wondering if anyone would be able to direct me to a breif description on how oscillators work and what they are as i need it for documentation for a science project Thanks |
Dannz (1668) | ||
| 361496 | 2005-06-06 00:17:00 | electronics.howstuffworks.com | godfather (25) | ||
| 361497 | 2005-06-06 06:04:00 | As well as electronic oscillators, there are mechanical and electro-mechanical oscillators using masses and springs etc. A Google of 'simple harmonic motion' will reveal a lot of useful info, both practical and mathematical. |
Terry Porritt (14) | ||
| 361498 | 2005-06-07 02:46:00 | There are also acoustic, biological, economic, climatic, astronomical (planetary etc.) and other oscillators. Their main commonality (if an oscillator is defined as anything which oscillates – you weren’t I think more specific than this) is that very similar mathematics, including as noted analysis of SHM, describes them all. Also to resolve/predict interesting and sometimes practically very important questions of what happens when an oscillating system starts to resonate (e.g. the Tacoma Narrows bridge collapse of 1940 in Washington State, USA). They can also be described/analysed by using models of any of these oscillating systems (preferably the one that the user understands best) to analyse/predict the behaviour of any of the others. Electrical analogue circuits are probably the type of analogue system most favoured by engineers for this latter purpose, although they also like mathematical descriptions, with the latter being those most favoured by the economists and astronomers. |
rugila (214) | ||
| 361499 | 2005-06-07 05:10:00 | I am thinking of a 4 pin electrical oscillator Example Here (www.sicom.co.nz) | Dannz (1668) | ||
| 361500 | 2005-06-07 05:36:00 | hem.passagen.se | godfather (25) | ||
| 361501 | 2005-06-07 06:36:00 | Whilst GFs site shows circuits, it doesn't actually explain the simple and basic fundamentals. A crystal oscillator is actually a mechanical oscillator that is kept vibrating by the circuitry. It uses the piezo electric effect, whereby if an electric field is applied across a quartz crystal, the dimensions of the crystal will change, and conversely if a crystal is stressed (like in a crystal pickup on turntables) it will produce electric charges. So if an alternating field is applied the crystal will vibrate. If the alternating field is at the mechanical resonant frequency of the crystal, then the interaction between the circuit and the crystal will maintain the oscillations. The process is actually self starting and self maintaining. The crystals are 'cut' to give specific frequencies. |
Terry Porritt (14) | ||
| 361502 | 2005-06-08 06:19:00 | A well known way to design an electronic oscillator: "design an amplifier". To make an amplifier you have to stop it oscillating. :( That 4-terminal Crystal Oscillator at South Island Components (at an surprisingly low price -- pity they haven't got any) has a resonant crystal element which provides frequency dependent positive feedback to a transistor amplifier. The "self starting" is provided by noise or switch-on transients. "Maintaining" requires some energy. The amplifier provides that, and the output. (In fact, it's not a 4-terminal device ... only 3 are used: +5V, gnd, and output). |
Graham L (2) | ||
| 361503 | 2005-06-08 07:08:00 | Thankyou for all your input | Dannz (1668) | ||
| 361504 | 2005-06-09 06:12:00 | A very good introductory book is The Art of Electronics by Horowitz and Hill. It's quite expensive, but public libraries should have it. | Graham L (2) | ||
| 1 2 | |||||