Chip amp power supply- a beginners guide

Here are a couple more close-ups

top1.jpg


top2.jpg
 
one switch of ON/OFF, the other is the bulb BYPASS.

Is the bulb off when there is no load and the ON switch is held down?
Does the bulb react in any way when you connect a load and hold the ON switch down?
Can you arrange a big load to light the bulb? and does it o off when you press the BYPASS?
 
AndrewT said:
one switch of ON/OFF, the other is the bulb BYPASS.

Is the bulb off when there is no load and the ON switch is held down?
Does the bulb react in any way when you connect a load and hold the ON switch down?
Can you arrange a big load to light the bulb? and does it o off when you press the BYPASS?

Hi Andrew

When I connect the light bulb and press the on button the light, lights up for a second and then goes out. This happens when I have a 230R resistor between V- and ground


I will check the other combinations tonight and will also increase the value of the test resistor

Richard
 
AndrewT said:
one switch of ON/OFF, the other is the bulb BYPASS.

Is the bulb off when there is no load and the ON switch is held down?
Does the bulb react in any way when you connect a load and hold the ON switch down?
Can you arrange a big load to light the bulb? and does it o off when you press the BYPASS?


I am using a 40w bulb for this test


Q1> Is the bulb off when there is no load and the ON switch is held down?

A1> The bulb lights for less than a second


Q2> Does the bulb react in any way when you connect a load and hold the ON switch down?


A2> As above


Q3> Can you arrange a big load to light the bulb? and does it o off when you press the BYPASS?

A3> I placed a 1K3 resistor between V- and Ground, the bulb lights as above and the bypass switch has no effect.
 
Tidy on top...messy on bottom!

pcbbottom.jpg


This picture was taken before I added the link to the collector pin of the BD912, I have only added it to the -v side for the time being.

There is a blob of solder on the -v side where the zener and the J309 meet....I carelessly soldered the J309 one row too high and then had to bridge the connection.

I'm off to hit the hay!
 
Tripmaster said:



I am using a 40w bulb for this test


Q1> Is the bulb off when there is no load and the ON switch is held down?

A1> The bulb lights for less than a second


Q2> Does the bulb react in any way when you connect a load and hold the ON switch down?


A2> As above


Q3> Can you arrange a big load to light the bulb? and does it o off when you press the BYPASS?

A3> I placed a 1K3 resistor between V- and Ground, the bulb lights as above and the bypass switch has no effect.



this is not right.
The bulb must be off when both switches are off.
The bulb must not flash, not even briefly nor dimly, when the ON switch is pressed and there is no load.

The bulb must go out, if it is already glowing or lit, when the bypass switch is pressed.

A big load would be a kettle, fan heater, iron, toaster etc.