Hi masood u can measure it by using multimeter
Just put multimeter in 200mv dc and check across speakers terminal
dear srawnth,
thank u i have assembelled this circuit pcb by silheg.but protection relay is not availabe here.for this reason my project is pending.thanks regard
BD139 is not darlington, replace 4k7 with 1k5 in bias circuit and measure voltages on 47R and 680R resistors
Apex sir
I have changed 4.7k with 1.5k
Voltage across 680ohm is 1v
Voltage across 47ohm is 0.4v
With 30-0-30 VDC
Attachments
Masood,
use-DoublePole,58series,Those-2legs-of-the-relay,behind,,cut-them,,😀
285ohms-are12v,,1150ohms-are-24v
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yes! I changed 1k to 1.5k and 100R to 200R resistor. Thank you so much sir Apex and sir Alex mm!
Hi Mr.Mile.
I build ax-11 MK2 and I am very happy with the sound, the bass and middle and high tones to detail, but I got the same problem with vargas Mongos, where the transistors heat up quickly. I use 25-0-25 voltage vac, what should I do so that the transistor does not heat up quickly and be stable?
I build ax-11 MK2 and I am very happy with the sound, the bass and middle and high tones to detail, but I got the same problem with vargas Mongos, where the transistors heat up quickly. I use 25-0-25 voltage vac, what should I do so that the transistor does not heat up quickly and be stable?
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I forgot to mention that I place small heat sink for MJE350/40 and I also add a coil and a 10 ohm 7W wire wound resistors in parallel with the coil 18AWG about 22 turns on a 8 mm diameter cylinder and I notice that the amp stabilize I do not have any scope so I do heat feeling "touch" notice that the heat was lower and stable I did not have a darlington so I just drop a BD139 I mean this is me because I do not have much parts or better test tools I did as test and it works 🙂
Regards
Juan
Attachments
thanks a lot juan for your explant..i will try to put 10R/7or 5W parallel with the coil 22 turns 8mm diameter.
can i use 25-0-25 volt vac,juan?
can i use 25-0-25 volt vac,juan?
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amplifier Output Zobel is the R+C that connects the amplifier output back to the amplifier Ground.
The Thiele Network adds a R||L to the Output Zobel to create a 4 component output Network.
The Thiele Network adds a R||L to the Output Zobel to create a 4 component output Network.
is this you call zobel network,Andrew T?
Tomorrow i try to put zobel network or coil with R and i will post result immediately
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That is the Thiele Network.
It has an R+C in series to Ground
and
an R||L to the speaker load.
An Output Zobel has only the R+C part to Ground.
It has an R+C in series to Ground
and
an R||L to the speaker load.
An Output Zobel has only the R+C part to Ground.
Hi juan
I put R ll L already.but after 5 minute with minimum input,transistor still geting hot.
So what else should i do?
yes,,the load i am using 8ohms speaker
vcc 25vac is it too high?
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mr.mile.
current measurement is 21.9 mV at R0.22. but not constant...the size heatsink is 20cm x 8cm for tes only.
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