Functional Insulation: Insulation that is only necessary for the correct functioning of the equipment.For instance, there are five categories of insulation introduced in UL60950: The isolation requirement specifies different levels of input and output voltage-both steady state and transient state-by many agencies throughout the world like VDE and IEC in Europe and UL in the United States. Isolation is an important method to meet safety standards. When designing a power supply, complying with safety standards is essential to protect operators and other personnel from electric shock and hazardous energy. This article discusses the digital isolation techniques to address these issues with Analog Devices’ iCoupler ® products in digital power supply design. These issues limit optocoupler or transformer use in some high reliability, compact size, and long life applications. The transformer solution also has bulk size, magnetic saturation problems, etc. 1 However, the traditional optocoupler solution has low bandwidth and current transfer ratio (CTR), which causes wide variation with temperature and degradation with time problems. The challenge of isolation in a digital power supply is in sending digital or analog signals across the isolation barrier with fast speed, accuracy, and compact size. For these applications, isolation is often required. Digital power supplies are widely employed in high end server, storage, telecom brick module, etc. With the aggressive growth of the internet and communication infrastructure, digital control techniques are becoming more and more popular in the power systems of telecom, networking, and computers because they can offer attractive advantages, including flexibility, component count reduction, advanced, control algorithm, system communication, low sensitivity to external noises, and parameter variation. If you could replace linear regulation with switch mode control (PWM) you avoid a lot of heat problems.Isolation in Digital Power Supply-Why and How and still it is likely for the Mosfet to explode. This is huge! You need a big heatsink with fan. Consider to replace it with a lower value one.Īlso the worst case power dissipation of the Mosfet is about 300W. The current measurement shunt has high power dissipation.
#DC VOLATGE GROUND ISOLATOR INSTALL#
* would install low pass filters in the analog paths to reduce noise.
( thus using a cheap external DAC improves overall performance) They have poor accuracy, poor resolution, poor linearity and poor precision. * don't like the ADCs and DACs of the ESP32. Its easier, cheaper and more precise and reliable to do the correction in software. * don't like the potis in the analog paths. This is a good (digutal) indicator of: regulation is O.K. my approach would be this:ĮSP32, SPI -> isolation -> cheap SPI DAC -> current control loop -> load currentĬurrent control output -> comparator -> optocoupler -> ESP32Īs soon as the current control loop is out of regulation the current_control_loop_output immediately saturates close at VCC. Thus - my personal way is - to place the isolation into digital paths. If there is a big deviation you may just assume the the current control loop is "out of regulation".īut why does this matter for the "isolation problem"?īecause in your application now are two analog paths that need to be isolated.īut isolating analog paths is rather difficult and usually generates rather big. Thus the measurement of the current does not give much reliable information. In most cases you will read back the expected value. * DAC -> current control loop-> load current
(Otherwise you need to measure the load voltage to be able to regulate the power) > So indeed it seems to be a "constant current control".
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