Hello Crystal,

At 03:11 PM 11/30/98 -0500, *Crystale \"The Angel\" Vail* wrote:
>Hello,
>I am a college student and this is my first time using the forum.
>
>Anyway, I need help with two engineering projects I have been assigned.
>Don't worry, you won't be helping me to cheat or anything because we have
>been advised to access all available resources.

Well, I'll try to wipe the cobwebs off my mind ...

>The first assignment is to build a power supply.  I don't even know where
>to start!!!

Start from where the power comes into the supply.

>The power supply has to be able to run the tape deck of a walkman.  The
>transformer has to step the voltage down from 120Volts to about 4.5Volts.

Ok, 120/4.5 = roughly 26.6

>There's four diodes connected creating a 4-way rectifier.

Think you mean FULL WAVE rectifier.

> Theres also a
>resistor, capacitor, and zener diode connected in the circuit.

Well, the cap filters out the ripple from the transformer.
The resistor limits the current draw and ripple.
The diode sets the voltage at the output.

>The second assignment is to build a class A amplifier with maximum
>semetrical swing

Ok, first I hope you mean Common Emitter.

Anyway, that means to draw a load line with the collector current
Ic as the vertical and the voltage across the emitter and collector
Vce as the horizontal.  Full load maximum current draw has a max
Ic and Vce = 0.  No load has Ic = 0 and Vce equal to some value
such as the value of the power supply.  Connect those two points
with a straight line and your "quiescent" point or Q-point should
be right in the middle of the slope.

> and 45dB of gain or more,

Hope they mean voltage gain, or, 20*log(Vout/Vin) = 45
That means Vout/Vin = (about) 178

> using a 2N222A transistor

Think you mean 2N2222A.  Very common part.

> and 1 meg of input impedeance or more.

Depending upon how you setup your input circuitry,
Rinput is basically  = All input resistors and (Beta*Remitter) in parallel

>I don't even know what half of these things mean.

Check your textbook for the above concepts.

> Also, for both
>projects, we need to find the values of all of the components, they are
>not given.

Yep.  That sounds like a lab.

>Any help would be greatly appreciated.

Well, I hope I've helped.
Others are probably more capable than I.
Stick around and maybe more will join in.

>Thank you for your attention.

Your welcome.

Doug

################################################################
DesignerCouncil E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c
################################################################
To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body:
To subscribe:   SUBSCRIBE DesignerCouncil <your full name>
To unsubscribe:   SIGNOFF DesignerCouncil 
################################################################
Please visit IPC's web site (http://www.ipc.org) "On-Line Services" section for additional information.
For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312
################################################################