psu design with the lm350

[tjalf]

hi there.. hope you can help me...

i got a 24VAC 3,6A transformer and i need to make an 6.3V 3A powersupply...

can the lm350 be used for this?? i have looked at the pdf files from national.com but my brain cant get the idea of the schematics...

is the someone who could help me??

thanks for your time

 

[Nigel Goodwin]

hi there.. hope you can help me...

i got a 24VAC 3,6A transformer and i need to make an 6.3V 3A powersupply...

can the lm350 be used for this?? i have looked at the pdf files from national.com but my brain cant get the idea of the schematics...

The transformer is really far too high a voltage, the regulator would need to dissipate about 100W of heat!.

You mention 6.3V, this is the standard heater voltage for 'E' series valves, is it for a valve heater supply?.

 

[akg]

hi there.. hope you can help me...

i got a 24VAC 3,6A transformer and i need to make an 6.3V 3A powersupply...

can the lm350 be used for this?? i have looked at the pdf files from national.com but my brain cant get the idea of the schematics...

is the someone who could help me??

thanks for your time

the o/p voltage is V=1.25(1+R2/R1)

so for ur needs make R2, 4 times that of R1 ,
R1- 470 and R2 1.9K will do (1.8K+100)

 

[tjalf]

hi there.. hope you can help me...

i got a 24VAC 3,6A transformer and i need to make an 6.3V 3A powersupply...

can the lm350 be used for this?? i have looked at the pdf files from national.com but my brain cant get the idea of the schematics...

The transformer is really far too high a voltage, the regulator would need to dissipate about 100W of heat!.

You mention 6.3V, this is the standard heater voltage for 'E' series valves, is it for a valve heater supply?.

thats correct... how small transformer should i den have??
i can get an 2*6v 2×3333mA transformer to an ok price would it be to small??

 

[Nigel Goodwin]

thats correct... how small transformer should i den have??
i can get an 2*6v 2×3333mA transformer to an ok price would it be to small??

Historically valve heaters were fed with AC directly from a transformer, there's no need for either DC or regulation. If you can't find a specific heater transformer the 6V one mentioned above should work fine.

 

[Russlk]

If you valve is an old directly heated filament, like 01A, 6A3 or 6A4, then DC power to the heater will reduce hum but for modern indirectly heated cathodes AC power is fine.