TLx94 manipulation

[807tubenut]

Lot's of things CAN be done to the tlx94 and compatible series, to make them more user friendly (from an adjustment standpoint)


Simple circuit modification, that will allow the dead time controller in the x94 series, to be changed! IE: raised and lowered


If you do not understand what this circuit does, please do not attempt to modify your amp, doing this mod could potentially raise the rail voltage high enough to explode your filter capacitors, potentially harming yourself or others, not to mention the 3,000 other bad thing's that are more then likely to happen.


As a side note, pins 1 and 2 handle your Over voltage protection, and pins 15 and 16 are under voltage protection.


If you want to change the switching frequency (not a good idea to move to far without a transformer re-winding, as it will fall out of the efficiency range for that wind and wire ratio used on your transformer's, also it is possible to saturate your core, things heat up fast...



switching freq calculation is as follows.

Switching frequency = R1 x C1, divided by constant of 1.44

RI = Ra + Rb (kohm for R value, and uF for capacitor value)

[807tubenut]

No one found this interesting?



weaksauce....

[Perry Babin]

I didn't understand the reason it was posted. Was in response to someone's question or does it apply to some amp?

The DT input is rarely used to control the rail voltage. It's generally use at or near 0v which prevents it from increasing the deadtime. If the voltage on it were increased, the rail voltage would drop.

I don't understand the circuit. I wouldn't expect it to make a difference.

[807tubenut]

The circuit is simply a voltage divider for the dead time controllers reference, your not passing voltage, your changing it's oscillator's response to being drained, in this manner, you can control the DT of the TLx94 series, this circuit will allow you to raise and lower rail voltage, I have this and a few other mods dont to my orion 500 test amp.

[Perry Babin]

Orion doesn't use the pulse width to regulate their rail voltage. If you reduce the pulse width without rewinding the transformer, all you can do is limit the power, as far as I can see.

[807tubenut]

On this orion x500 playing with the pwm has given me an additional 5v worth of rail voltage, ill be playing with this a bit more later this week, on 2nd thought, I might have bumped my switching freq pot also...

[Perry Babin]

I would have expected the resistor to go to 5v if you wanted to change the dead time.

[807tubenut]

Pin 4 provides the voltage, the way it works, is your cap and resistor tie to ground, pin 4 charges the cap, while the resistor discharges the cap, pin 4 detects the time it takes to collapse the cap's charge, references that for it's duty cycle , and wash,rinse, and repeat.


On 2nd thought, just stick your scopes probe on pin 4 and watch the magic of a collapsing field oscillator.

[ian33]

what other mods you have?

[ian33]

for more power?