# from philippines here, need help in our school project :'(

#### immanic

Joined Oct 9, 2010
10
can someone please help us. we need a schematic design for our stepper motor(astrosyn 17pw-m003) driver. we need 5v, 1A.

(switching transistor for the driver of our stepper motor)
the triggering current needed for our power transistor(tip29a) is 10ma. but the output current of our controller is only 33 microamp.how can we make our controller output current 10 ma?

#### wayneh

Joined Sep 9, 2010
16,114
can someone please help us. we need a schematic design for our stepper motor(astrosyn 17pw-m003) driver. we need 5v, 1A.

(switching transistor for the driver of our stepper motor)
the triggering current needed for our power transistor(tip29a) is 10ma. but the output current of our controller is only 33 microamp.how can we make our controller output current 10 ma?
You need a current gain of ~300. I think there may be transistors that can do that, or just use 2 in a darlington pair. Or, you could use something like a comparator or op-amp to boost the signal. Op-amp is probably the best option if you have a circuit board with a power supply for it.

#### immanic

Joined Oct 9, 2010
10
for the base transistor problem,,, i agree that op amp is the best solution. tnx a lot ^^ can you help me with the driver that can give 5v and 1A?with a supply of 16v dc?

#### immanic

Joined Oct 9, 2010
10
the supply is transformer center tap 9v-9v

#### wayneh

Joined Sep 9, 2010
16,114
for the base transistor problem,,, i agree that op amp is the best solution. tnx a lot ^^ can you help me with the driver that can give 5v and 1A?with a supply of 16v dc?
What is the amperage rating of the 16v supply? You'll need at least 1A for "simple" solutions (linear voltage regulator, ie. 7805), and at least about 0.4A for ANY solution (SMPS).

#### immanic

Joined Oct 9, 2010
10
the rating is 2A

#### wayneh

Joined Sep 9, 2010
16,114
the rating is 2A
Now that I think about it, I think a standard 7805 is only rated to 0.5 A. A LM317T can take you to 1.5A with a good heat sink, so you should probably look up the datasheet for that one. It's very versatile to have around in your "bag of tricks".

#### marshallf3

Joined Jul 26, 2010
2,358
Most 7805 ICs I use are rated to 1A however the NCP7805TG low dropout regulator from ON Semi can go much higher.

#### immanic

Joined Oct 9, 2010
10
@wayneh, since we have both of the component, you suggested, we'll try both. thanks a lot, you're a big help. can i have followup questions if i encounter another problem?? aprex8 a lot

#### immanic

Joined Oct 9, 2010
10
@marshallf at what ampere rate does NCP7805TG gives?