Good morning Gentlemen!
As many of you will know, I am trying my hand at learning electronics. Because my main interests and application lie in the realm of audio, my focus is on electronic design for audio.
Now, I have found out that simulations using various Spice type software can assist greatly in the learning department with no danger attached. Catastrophic failure is far less demoralizing when it happens on your PC screen in some software as opposed to on a beautifully made PCB.
The one thing I have a real hard time simulating is a power supply for some reason. I have used LTSpice, Tina TI, and MultiSim. None of them get the power supply things quite right. I am sure it's not the fault of the software, but rather my own inadequacy in the use of the software.
On the software side, LTSpice is great but I am unable to join the Yahoo group in order to download components. This frustrated me so much for a couple of days that I ended up looking for something else. I found Tina TI, which I think is great and very easy to use, but the problem there is that the simulator is extremely CPU intensive. I finally ended up using MultiSim which is absolutely fantastic!
So, onto the actual reason for this post:
What I am simulating is this:
1. Create a dual output power supply, meaning a transformer with one primary and 2 secondary windings.
2. There are some mostly EMI filter components as well as a fuse on the primary side.
3. There is a full wave bridge rectifier with filter capacitors on the secondaries.
The issues I am having are:
1. I cannot find a way to "limit" the transformer in terms of the maximum VA rating. The voltage is easy enough to set by means of the windings ratio, but the current limit cannot be set as far as I can see.
2. The ratio of input current (primary winding side) to output current (secondary winding side) does not seem to calculate correctly. It seems as if the primary side draws 10 amps when the secondary side is drawing 10 amps. This does not make sense!
3. I know a typical well made transformer can provide up to 300% of its rated current safely for a very short burst duration. Can this be simulated? I think the Spice rules are pretty hard here - the math does not allow for this kind of thing as far as I know.
What I am trying to achieve:
1. I want to see how changing the values of components in the power supply will affect the output voltage and current.
2. Using a virtual oscilloscope in the software, I want to see how clean I can make the output of the power supply in terms of ripple, etc. I want to see what's happening in the supply lines when driving heavy loads, frequencies, etc.
Any pointers would be greatly appreciated! It may very well be that the only answer here is that I need to get my hands on some components, and wire them up and measure these things for real on the scope. If possible, I would rather have some more information before buying, but if building and measuring it is the only viable option then I am ok to do it.
Thanks for taking the time to read & please help me understand this if you have anything to share.
Kind Regards,
Ian.
As many of you will know, I am trying my hand at learning electronics. Because my main interests and application lie in the realm of audio, my focus is on electronic design for audio.
Now, I have found out that simulations using various Spice type software can assist greatly in the learning department with no danger attached. Catastrophic failure is far less demoralizing when it happens on your PC screen in some software as opposed to on a beautifully made PCB.
The one thing I have a real hard time simulating is a power supply for some reason. I have used LTSpice, Tina TI, and MultiSim. None of them get the power supply things quite right. I am sure it's not the fault of the software, but rather my own inadequacy in the use of the software.
On the software side, LTSpice is great but I am unable to join the Yahoo group in order to download components. This frustrated me so much for a couple of days that I ended up looking for something else. I found Tina TI, which I think is great and very easy to use, but the problem there is that the simulator is extremely CPU intensive. I finally ended up using MultiSim which is absolutely fantastic!
So, onto the actual reason for this post:
What I am simulating is this:
1. Create a dual output power supply, meaning a transformer with one primary and 2 secondary windings.
2. There are some mostly EMI filter components as well as a fuse on the primary side.
3. There is a full wave bridge rectifier with filter capacitors on the secondaries.
The issues I am having are:
1. I cannot find a way to "limit" the transformer in terms of the maximum VA rating. The voltage is easy enough to set by means of the windings ratio, but the current limit cannot be set as far as I can see.
2. The ratio of input current (primary winding side) to output current (secondary winding side) does not seem to calculate correctly. It seems as if the primary side draws 10 amps when the secondary side is drawing 10 amps. This does not make sense!
3. I know a typical well made transformer can provide up to 300% of its rated current safely for a very short burst duration. Can this be simulated? I think the Spice rules are pretty hard here - the math does not allow for this kind of thing as far as I know.
What I am trying to achieve:
1. I want to see how changing the values of components in the power supply will affect the output voltage and current.
2. Using a virtual oscilloscope in the software, I want to see how clean I can make the output of the power supply in terms of ripple, etc. I want to see what's happening in the supply lines when driving heavy loads, frequencies, etc.
Any pointers would be greatly appreciated! It may very well be that the only answer here is that I need to get my hands on some components, and wire them up and measure these things for real on the scope. If possible, I would rather have some more information before buying, but if building and measuring it is the only viable option then I am ok to do it.
Thanks for taking the time to read & please help me understand this if you have anything to share.
Kind Regards,
Ian.
