Hello everyone
I want to design a circuit. I'm a repairer of electronic goods but unfortunately I am not a circuit designer, not to the level whereby I can create a fairly complex circuit that works smoothly - my design tends to be a bit rough and ready.
Recently I've been repairing a good number of TFT monitors which operate on 12V DC supplies. Sometimes the monitors are supplied without the 12V chopper power supply adapters which means I have difficulty testing them as my benchtop power supply uses a standard mains transformer and a regulator connected to a pot which allows voltage control from 0 - 30V and the output current just isn't high enough despite the huge size of the transformer.
As I want the higher current but with the continued ability to alter the voltage level, I thought that a chopper power supply hooked up to a regulator would be better. I can use LM338T for voltage regulation.
I want to build the chopper power supply myself. I know a lot of people gawp at the thought because they are fairly complex circuits, but what about if a lot of the 'extras' in the circuit were removed, like the optocoupling and other perhaps unnecessary complexities.
Most TFT monitors (and laptops that come in for repair) need from 2.5A to 4A and a variable supply using a chopper circuit would be ideal, while giving me high current and variable voltage to use on other devices when needed.
I'd take mains voltage, rectifying and smoothing it I can design myself, but I'm not sure how to go about creating the high frequency which chopper circuits use. I have plently of chopper transformers about (from TV chopper supplies) and planned to use one winding with a center tap and then use a push-pull design at high-frequency. Nothing fancy, if that's workable.
I'd like to then use any of the secondary windings that produce around 35V, rectify, smooth, and supply to a lead.
Is it possible to design a very simple circuit to do this and does anyone feel up to the task of helping me please? I can make the PCB using photo-etch board and I have a good stock of components and can get hold of others easily.
I'd really appreciate any technical help and advice on this.
Thanks.![Big Grin :D :D](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
I want to design a circuit. I'm a repairer of electronic goods but unfortunately I am not a circuit designer, not to the level whereby I can create a fairly complex circuit that works smoothly - my design tends to be a bit rough and ready.
Recently I've been repairing a good number of TFT monitors which operate on 12V DC supplies. Sometimes the monitors are supplied without the 12V chopper power supply adapters which means I have difficulty testing them as my benchtop power supply uses a standard mains transformer and a regulator connected to a pot which allows voltage control from 0 - 30V and the output current just isn't high enough despite the huge size of the transformer.
As I want the higher current but with the continued ability to alter the voltage level, I thought that a chopper power supply hooked up to a regulator would be better. I can use LM338T for voltage regulation.
I want to build the chopper power supply myself. I know a lot of people gawp at the thought because they are fairly complex circuits, but what about if a lot of the 'extras' in the circuit were removed, like the optocoupling and other perhaps unnecessary complexities.
Most TFT monitors (and laptops that come in for repair) need from 2.5A to 4A and a variable supply using a chopper circuit would be ideal, while giving me high current and variable voltage to use on other devices when needed.
I'd take mains voltage, rectifying and smoothing it I can design myself, but I'm not sure how to go about creating the high frequency which chopper circuits use. I have plently of chopper transformers about (from TV chopper supplies) and planned to use one winding with a center tap and then use a push-pull design at high-frequency. Nothing fancy, if that's workable.
I'd like to then use any of the secondary windings that produce around 35V, rectify, smooth, and supply to a lead.
Is it possible to design a very simple circuit to do this and does anyone feel up to the task of helping me please? I can make the PCB using photo-etch board and I have a good stock of components and can get hold of others easily.
I'd really appreciate any technical help and advice on this.
Thanks.