Hello,

I build this (http://oh8jep.kotinet.com/eb104/pw_eb104.gif) power supply for
the EB104-amplifier. Unfortunately I can't get BUX22 and so I used BUX98A.

The transformer-output is a little bit lower, so the DC is 62V. But the
supply works and I get 50V output. So far so good.

My eb104 is still not assembled, so I tested the supply with two Osram
halogen lamps HLX64655 250W and 24V in series connexion.

When the lamps are connected and the transformer is connected to the
mains supply sometimes the lamps will light. The current ist ca. 11
ampere. But the current behind the rectifier is 21A!!! But the output
voltage is still 50V.

Often the lamps will not light an the voltage drops down to zero.

If I try four lamps, a series of two parallel lamps, they never light.

When the lamps are not connected and I connect the power supply to the
mains supply and after that I connect the lamps the voltage drops always
down to zero.


So you see, a lot of problems.

Any hints?


Vy 73 Holger/ DL9HDA

So you see, a lot of problems.

Any hints?


Vy 73 Holger/ DL9HDA


Absolutely Holger. Use something besides light bulbs for a load. They
probably want 500 Amperes when they're cold.

W4ZCB

Harold E. Johnson wrote:

Absolutely Holger. Use something besides light bulbs for a load. They
probably want 500 Amperes when they're cold.
W4ZCB

Hello Harold, I hadn't previously considered this. My mistake. So I'll try
to find some suitable resistors ...

Holger / DL9HDA

Holger Doerschel wrote:
Hello,

I build this (http://oh8jep.kotinet.com/eb104/pw_eb104.gif) power supply for
the EB104-amplifier. Unfortunately I can't get BUX22 and so I used BUX98A.

The transformer-output is a little bit lower, so the DC is 62V. But the
supply works and I get 50V output. So far so good.

My eb104 is still not assembled, so I tested the supply with two Osram
halogen lamps HLX64655 250W and 24V in series connexion.

When the lamps are connected and the transformer is connected to the
mains supply sometimes the lamps will light. The current ist ca. 11
ampere. But the current behind the rectifier is 21A!!! But the output
voltage is still 50V.

Often the lamps will not light an the voltage drops down to zero.


Seems like i read somewhere the EB104 didnt work best at 50 volts, I
believe it was 41 volts, maybe lower.

Howard probably knows about this.


Jimmie

If I try four lamps, a series of two parallel lamps, they never light.

When the lamps are not connected and I connect the power supply to the
mains supply and after that I connect the lamps the voltage drops always
down to zero.


So you see, a lot of problems.

Any hints?


Vy 73 Holger/ DL9HDA

wrote:

Holger Doerschel wrote:
Hello,

I build this (http://oh8jep.kotinet.com/eb104/pw_eb104.gif) power supply for
the EB104-amplifier. Unfortunately I can't get BUX22 and so I used BUX98A.

The transformer-output is a little bit lower, so the DC is 62V. But the
supply works and I get 50V output. So far so good.

My eb104 is still not assembled, so I tested the supply with two Osram
halogen lamps HLX64655 250W and 24V in series connexion.

When the lamps are connected and the transformer is connected to the
mains supply sometimes the lamps will light. The current ist ca. 11
ampere. But the current behind the rectifier is 21A!!! But the output
voltage is still 50V.

Often the lamps will not light an the voltage drops down to zero.


Seems like i read somewhere the EB104 didnt work best at 50 volts, I
believe it was 41 volts, maybe lower.

Howard probably knows about this.


I assume that this means 41 volts gives the best IMD figure, not the
lowest drive or highest power output. Maybe this is also a safe
operating point with higher voltages requiring much more in the way of a
heat sink or fan for safe operation without having to reduce the zero
signal current to the point of more cross over distortion.