Polyphase rectifier: Calculating the diodes needed.

  • Thread starter Thread starter Simple10
  • Start date Start date
  • Tags Tags
    Diodes Rectifier
AI Thread Summary
The discussion focuses on calculating the necessary diodes for a three-phase rectifier based on a theoretical coil generating 6.21V and 15.33A. The user seeks guidance on diode specifications, including voltage and amperage ratings, as well as reverse voltage ratings, noting that the voltage drop across diodes may vary depending on the chosen components. They also inquire about the implications of adding more phases on diode requirements and whether a dump load is necessary when charging batteries. The user has identified potential diode options from Mouser, considering a 200V, 16A diode, and is verifying if this would suffice for their application. The conversation emphasizes the relationship between Tesla strength and current production in the context of AC to DC conversion.
Simple10
Messages
15
Reaction score
0
Hello,

I have created a theoretical coil of
170 turns*.4871 Tesla's*.0045m^2/.06 seconds=6.21V (Faraday of course.)

ohm's of the coil=.405
6.21V/.405ohms=15.33A

The equation I used
-N * curl*B*A/curl*t
N=number of turns; B=Tesla's; A=area of the coil; t=Time; curls cancel out.
(To calculate Time I used 1000 rpm/60=16.666 rps;1 second/16.666 rps=.06 seconds)
(To calculate Tesla's I chose a magnets surface gauss, 4871 and converted to Tesla's; 10,000 gauss=1 Tesla)

Lets say I have 9 coils with 3 phases:
http://www.allaboutcircuits.com/vol_3/chpt_3/4.html#03267.png
How do I calculate the Diodes I will need for the 3 Phase Rectifier? (see above link for schematic.)
If I had more phases will that change what diodes are needed? (see above link for 6 phase schematic.)
What voltage and amperage ratings for diodes?
What reverse voltage ratings for diodes?
Will the voltage drop across the diodes depend on the diodes I choose for the system?
Is a dump load nescessary if I were charging batteries and the batteries were full?


After rectification 111.78Vdc @ 46A. (This does not account for any voltage drop through the rectifier.)

Google seems to return non pertinent info about calculating for diodes.
Would Wolfram Alpha be better in this area?

P.S.

My goal is to understand the generating of Alternating Current and it's conversion to Direct Current.
 
Last edited:
Engineering news on Phys.org
My voltage and amps out is incorrect.
For the 3 phases it's 37.26 Volts and 46 Amps

I checked mouser form the first sticky for diodes.
I know that diodes allow voltage and amps to travel in one direction and prevent it going in the opposite direction.
My Volts on one side is 18V the other side 37V. Reverse Voltage I think would be 37V.
Second, Continuous current through the diode. I have 15 Amps.
I think I need a diode that would handle <37V and at least 15A.
I found Power Diodes from 200V reverse and 16A continuous up to 1400V reverse and 16A.
Voltage drop for all of these is 1.2V per Diode.

Would the 200V, 16A be sufficient?

If I add 3 more phases for 6 phases total that would be 37V @ 92A. Is this correct?

I also noticed the higher the Tesla's the more current produced.
 
Thread 'Weird near-field phenomenon I get in my EM simulation'
I recently made a basic simulation of wire antennas and I am not sure if the near field in my simulation is modeled correctly. One of the things that worry me is the fact that sometimes I see in my simulation "movements" in the near field that seems to be faster than the speed of wave propagation I defined (the speed of light in the simulation). Specifically I see "nodes" of low amplitude in the E field that are quickly "emitted" from the antenna and then slow down as they approach the far...
Hello dear reader, a brief introduction: Some 4 years ago someone started developing health related issues, apparently due to exposure to RF & ELF related frequencies and/or fields (Magnetic). This is currently becoming known as EHS. (Electromagnetic hypersensitivity is a claimed sensitivity to electromagnetic fields, to which adverse symptoms are attributed.) She experiences a deep burning sensation throughout her entire body, leaving her in pain and exhausted after a pulse has occurred...
Back
Top