Hi there!
Would be grateful for help regarding the following problem.![Smile :) :)](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
Translated from my textbook the problem sounds:
Quote-------------------
"By means of a photosensor and a comparator 5V is given when darkness,
and 0V when daylight. The signal generated is maximum 10mA. A lamp, which
consumes 800mA at 24V shall light when it is dark. To accomplish this, a
transistor swith is used. Your task is to calculate and dimension the
resistance, and draw the corresponding circuit.
The transistor withstands a current of maximum 1A, .i.e. Ic,max = 1A, and has hFE = 150 times (i.e. the beta-value).
Also U(BE) ~ 0,6V and U(sat) ~ 0V.
The circuit does not have to include the photocell and the comparator,
instead only the darkness/light signal is assumed." -----------end quote
I have attached a picture-file where my idea of how the circuit should look like, is shown. The answer to this problem according to the book is:
440 < Rb < 810 Ohm
Would be very thankful for some help here. .....![Eek! :eek: :eek:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
Thanks!
Would be grateful for help regarding the following problem.
Translated from my textbook the problem sounds:
Quote-------------------
"By means of a photosensor and a comparator 5V is given when darkness,
and 0V when daylight. The signal generated is maximum 10mA. A lamp, which
consumes 800mA at 24V shall light when it is dark. To accomplish this, a
transistor swith is used. Your task is to calculate and dimension the
resistance, and draw the corresponding circuit.
The transistor withstands a current of maximum 1A, .i.e. Ic,max = 1A, and has hFE = 150 times (i.e. the beta-value).
Also U(BE) ~ 0,6V and U(sat) ~ 0V.
The circuit does not have to include the photocell and the comparator,
instead only the darkness/light signal is assumed." -----------end quote
I have attached a picture-file where my idea of how the circuit should look like, is shown. The answer to this problem according to the book is:
440 < Rb < 810 Ohm
Would be very thankful for some help here. .....
Thanks!