[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

*To*: tesla@xxxxxxxxxx*Subject*: Re: SISG PC BOARDS*From*: "Tesla list" <tesla@xxxxxxxxxx>*Date*: Sat, 27 May 2006 12:54:10 -0600*Delivered-to*: testla@xxxxxxxxxx*Delivered-to*: tesla@xxxxxxxxxx*Old-return-path*: <vardan01@xxxxxxxxxxxxxxxxxxxxxxx>*Resent-date*: Sat, 27 May 2006 12:43:01 -0600 (MDT)*Resent-from*: tesla@xxxxxxxxxx*Resent-message-id*: <fpn0MiZkJeH.A.di.12JeEB@chip1>*Resent-sender*: tesla-request@xxxxxxxxxx

Original poster: "Gerry Reynolds" <gerryreynolds@xxxxxxxxxxxxx>

Original poster: "Mike" <mike.marcum@xxxxxxxxxxxx> If I was ever in doubt I just coated the traces with solder. Mike

If there ever is a problem, this will certainly help :-)) Gerry R

----- Original Message ----- From: "Tesla list" <tesla@xxxxxxxxxx> To: <tesla@xxxxxxxxxx> Sent: Thursday, May 25, 2006 8:27 AM Subject: Re: SISG PC BOARDSOriginal poster: "Gerry Reynolds" <gerryreynolds@xxxxxxxxxxxxx> Hi Mark,These things can be somewhat difficult to calculate. I didnt spendany time figuring out the scale factor on your trace widths and Iassume the board is using 2 oz copper (being an outer layer). Imthinking that what you have done is probably reasonable. I believethere are two issues with pc layout - heat generated in the trace(and you need to know the Irms to figure this out), and metalmigration (peak current is the issue here and resulting currentdensities). I just dont have any numbers. Im wondering if youever turn the board if there is any reason to not fatten up thetraces as much as possible.Gerry R.Original poster: "Mark Dunn" <mdunn@xxxxxxxxxxxx> Gerry: Good question. Maybe you can help me here. My trace calculations are based on pure DC and I do not know how to correct for the high frequency. What I did is come close to the cross-sectional area of the CDE942 leads so on that basis of that I should be able to push 500 amps. Now here is what I tried with math. See if you think I'm on the right track. Based on simple DC trace calculations I have: 24 amps give a 10 Deg C rise. 38 amps a 38 Deg C rise. The above values are based on dual(top and bottom) 125 mil traces in 3 oz copper. Now at 460 BPS I have 2130 uS "off-time" (cap charging time) and 43 uS "on-time" for ring-up and ring-down with my RSG(Note - Terry's testing suggests the "on-time" might dramatically increase). So maybe we can compute the average current during the whole break cycle to consider the thermal effect. If we have 500 amps during the "on-time" and near zero during the "off-time" then the average current is 43/2173*500 = 10 amps avg current. Subsequent to my board design, Terry found the "on-time" might jump to 150uS. If we use that measure then 150/2173*500 = 35 amps avg current. Critique of this calc would be much appreciated. Mark >Original poster: "Gerry Reynolds" <gerryreynolds@xxxxxxxxxxxxx> >Hi Mark, >How much current do you estimate the traces (high current path) on >your layout can take?? Gerry R.

- Prev by Date:
**Re: Continuously variable primary** - Next by Date:
**Re: Continuously variable primary** - Previous by thread:
**Re: SISG PC BOARDS** - Next by thread:
**Re: Frequency Splitting** - Index(es):