ROWUK on power supplies
Jan 29, 2008 13:31:15 GMT
Post by rowuk on Jan 29, 2008 13:31:15 GMT
I am no electrical genius so what I have to say may or may not fit your picture, but maybe there is something here that could help somebody!
I really like analogies. They can make things more easily understood if they are correct. They can also lead us to other solutions by involving other disciplines.
A simple power supply is often compared to a bucket of water with a valve attached to the bottom. We fill the bucket up with water and draw what we need as we need it through the valve and attempt to keep the bucket full by pouring water in as it is used. Comparing this to electronics, we have mains voltage that we transform into a useful size rectify to pulsating DC and let that "pour" into the capacitor, our electronic bucket. As long as our source of water is sufficient, the bucket does not run dry and we have a continuous source of water.
We can make the bucket bigger which increases the amount of water AND decreases the effects of water ripples that are caused when filling the bucket up during operation. This also works electronically by using bigger capacitors. The down side: when starting the process, we have to let the big bucket get full and then stabilize before expecting smooth operation.
If we demand a perfectly smooth flow of water or electricity, our simple bucket filter is not adequate. We could use the first bucket to fill a second one and would have a bit of isolation from the mains at the same time. This is accomplished electronically with a RC circuit. The rectifiers are connected to the first line of capacitors and then we have a resistor and the second "bucket".
Regulation requires a more active approach to filling the bucket up. Conventional toilets have a valve to refill when the water level goes down. Depending on the sensitivity of the valve and the pressure of the water, the refill cycle can cause more problems than it cures if a perfectly smooth flow of water is required. We have to match the power demands to the regulator electronically too! A conventional regulator needs 3V more input than the output to regulate properly. This 3v more has to available also when the power supply is loaded by the electronic device and if there are variances in the mains voltage.
Simple regulation is useful as long as the mains is stable AND the equipment being powered is not sensitive. We can stabilize the mains voltage with a good uninterruptable power supply. I have had good luck with the APC RT series that regenerates a 50/60hz sine wave. The equipment being powered by the power supply sometimes requires additional circuitry to give optimal sonic results. Maybe we have someone here that can also offer this in non-technical terms?
I really like analogies. They can make things more easily understood if they are correct. They can also lead us to other solutions by involving other disciplines.
A simple power supply is often compared to a bucket of water with a valve attached to the bottom. We fill the bucket up with water and draw what we need as we need it through the valve and attempt to keep the bucket full by pouring water in as it is used. Comparing this to electronics, we have mains voltage that we transform into a useful size rectify to pulsating DC and let that "pour" into the capacitor, our electronic bucket. As long as our source of water is sufficient, the bucket does not run dry and we have a continuous source of water.
We can make the bucket bigger which increases the amount of water AND decreases the effects of water ripples that are caused when filling the bucket up during operation. This also works electronically by using bigger capacitors. The down side: when starting the process, we have to let the big bucket get full and then stabilize before expecting smooth operation.
If we demand a perfectly smooth flow of water or electricity, our simple bucket filter is not adequate. We could use the first bucket to fill a second one and would have a bit of isolation from the mains at the same time. This is accomplished electronically with a RC circuit. The rectifiers are connected to the first line of capacitors and then we have a resistor and the second "bucket".
Regulation requires a more active approach to filling the bucket up. Conventional toilets have a valve to refill when the water level goes down. Depending on the sensitivity of the valve and the pressure of the water, the refill cycle can cause more problems than it cures if a perfectly smooth flow of water is required. We have to match the power demands to the regulator electronically too! A conventional regulator needs 3V more input than the output to regulate properly. This 3v more has to available also when the power supply is loaded by the electronic device and if there are variances in the mains voltage.
Simple regulation is useful as long as the mains is stable AND the equipment being powered is not sensitive. We can stabilize the mains voltage with a good uninterruptable power supply. I have had good luck with the APC RT series that regenerates a 50/60hz sine wave. The equipment being powered by the power supply sometimes requires additional circuitry to give optimal sonic results. Maybe we have someone here that can also offer this in non-technical terms?