Hello,
I have a project that is giving me problems and I'm looking for a little insight. First of all, the disclosures. I have to try and use this method of control as much as possible. That being said, I know there may be better ways of doing this, but I ask that only those that can help with this particular method respond.
I have a 24V 250W halogen bulb that I need to be able to set to 82% and 55% brightness. I am doing this with a PWM signal of 500Hz 0-5V (see attached schematic). The power supply I am using is a Mean Well EPP-300-24 (24Vdc 300W) and according to the data sheet, it does not require a minimum current to turn on.
When I power the circuit complete, the PSU and bulb flash about every second (its like the PSU is trying to start but can't for some reason). If I disconnect the bulb, the PSU starts with no problem and is able to power an auxiliary board that is controlling other circuitry (a 12v cooling fan via a voltage regulator and other low voltage stuff).
My concern is that there is a problem between the frequency of the SMPS and the frequency with which I am trying to control the output to the lamp. Can anyone confirm this? Is there any way around this (change to the circuit, not to the method)? Thanks.
I have a project that is giving me problems and I'm looking for a little insight. First of all, the disclosures. I have to try and use this method of control as much as possible. That being said, I know there may be better ways of doing this, but I ask that only those that can help with this particular method respond.
I have a 24V 250W halogen bulb that I need to be able to set to 82% and 55% brightness. I am doing this with a PWM signal of 500Hz 0-5V (see attached schematic). The power supply I am using is a Mean Well EPP-300-24 (24Vdc 300W) and according to the data sheet, it does not require a minimum current to turn on.
When I power the circuit complete, the PSU and bulb flash about every second (its like the PSU is trying to start but can't for some reason). If I disconnect the bulb, the PSU starts with no problem and is able to power an auxiliary board that is controlling other circuitry (a 12v cooling fan via a voltage regulator and other low voltage stuff).
My concern is that there is a problem between the frequency of the SMPS and the frequency with which I am trying to control the output to the lamp. Can anyone confirm this? Is there any way around this (change to the circuit, not to the method)? Thanks.