Connecting speakers in series and in parallel

When connecting an amplifier to a speaker it is important to match the impedance of the amplifier to the speaker for maximum power transfer:

On the circuit below we have an 8 ohm amplifier connected to two 4 ohms speaker in series to get 8 ohms (4+4) and therefore the amplifier impedance is equal to the speaker impedance.

If you don’t observe this principle then you will overload the amplifier and eventually it will blow.

  

Simple test for Cathode ray tube (CRT) bad or not.

To do this test, be sure you have the screen voltage presence and the heater is lighted and HV is present.

China TV (La76931) No raster, picture or sound

Clifford May Johannesburg South Africa

Hi Humphrey,

I've got a problem with this TV as you will see on the schematic I've got all voltage except 5volt on n552. 12v is ok on n551 but no 5volt coming out of n552. It gives me 1.2volt. I also changed transistor n552 but still the same. I desperately need your help please. Thanks in advance.

Kind Regards

Clifford