because in reality, there are losses (in form of heat) from transformer and from the amplifier device. 😀
It was obvious that there were losses

when i on the speaker protection circuit of BA1200 LED is on what does it mean
Protect LED is on if relay is off, after delay time (few secs) relay goes on and protect led off.
Protect LED is on if relay is off, after delay time (few secs) relay goes on and protect led off.
thank you sir
it is working at 14volts but not working with 12Volts
Last edited:
thank you sir
it is working at 14volts but not working with 12Volts
Replace 470k with 220k
Replace 470k with 220k
thank you sir its working with 12volts
is that important to use 10ohm , and 10uH for SR200
thank you sir its working with 12volts
is that important to use 10ohm , and 10uH for SR200
Use 1uH not 10uH
how to make 1uH sir. .
short air-core cylindrical coil:

L = inductance (µH)
r = mean radius of coil (in)
l = physical length of coil winding (in)
N = number of turns
d = depth of coil (outer radius minus inner radius) (in)
HI guys, I'm new here, and busy study building power amps, I had me the BA1200, but I struggle to set bias and dc offset. Please can one of you help me or assist me please?
short air-core cylindrical coil:
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L = inductance (µH)
r = mean radius of coil (in)
l = physical length of coil winding (in)
N = number of turns
d = depth of coil (outer radius minus inner radius) (in)
hello jaagut i have made the on 10mm diameter with 1.2mm thick copper , 12 turns.
is this coil is enough?
Attachments
could you confirm the measurement for L and D as shown in the picture?
D= 10mm
L= 20mm
D= 10mm
L= 20mm
r = D/2 = 10/2 = 5 mm or 5/25.4 inches
L = 20 mm or 20/25.4 inches
L = r*r * N*N / (9*r + 10*L)
= 5*5/(25.4*25.4) * 13*13 / (9*5/25.4 + 10*20/25.4)
= 0.679 uH
you need to increase the number of turns or the diameter of the coil until you'll have 1uH value.
ex.
either
you make the number of turns to 16, maintain diameter and length
or
you make the diameter to 12mm, maintain length and number of turns.
D in the formula is the mean diameter of the coil.
If the inside diameter is d and the wire is 1.2MM diameter then D= d+1.2
r = D/2 = d+0.6
for a mandrel of 10mm diameter d is likely to be 10.1 to 10.2mm giving r~5.6 to 5.7mm or ~0.222
If the inside diameter is d and the wire is 1.2MM diameter then D= d+1.2
r = D/2 = d+0.6
for a mandrel of 10mm diameter d is likely to be 10.1 to 10.2mm giving r~5.6 to 5.7mm or ~0.222
i have checked it with LCR meter its .9uh
then i guess you can use that. 🙂
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