Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Using Tip 122 power amp

Status
Not open for further replies.

sreerajps

Newbie level 4
Joined
Sep 3, 2009
Messages
5
Helped
1
Reputation
2
Reaction score
1
Trophy points
1,283
Location
bangalore
Activity points
1,316
I have a signal generator 10Hz- 1Mhz. 5v-15v adjustable. I want to drive a simple coil wonted on a core. Its changes the N-S poles according the signal frequency. But i want it with high current using TIP122. I have another source of 48V 2A DC. Do i need any additional series resistance with the sig gen to base of tip ? please help me? Can i drive this tip122 with signal generator ? :?:
 

sreerajps

Newbie level 4
Joined
Sep 3, 2009
Messages
5
Helped
1
Reputation
2
Reaction score
1
Trophy points
1,283
Location
bangalore
Activity points
1,316
circuit.PNG

Is this is the way to connect ? :arrow: diagram is attached.
The winding still works if it directly connected to the sig gen. But i need a forceful pull push with the field. So i should apply some more current in to the winding.
 
Last edited:

mister_rf

Advanced Member level 5
Joined
Feb 26, 2008
Messages
1,874
Helped
1,040
Reputation
2,088
Reaction score
953
Trophy points
1,393
Location
Romania
Activity points
11,528
Don’t forget about a standard protection which puts a diode in antiparallel with the inductive load.
 

Attachments

  • diode protection.GIF
    diode protection.GIF
    7.8 KB · Views: 16

alexan_e

Administrator
Joined
Mar 16, 2008
Messages
11,895
Helped
2,021
Reputation
4,158
Reaction score
2,031
Trophy points
1,393
Location
Greece
Activity points
64,377
The TIP1xx series Darlingtons have internal reverse-EMF protection diodes, as they're made for driving inductive loads, it shouldn't be necessary to add more external diodes.

Alex
 

sreerajps

Newbie level 4
Joined
Sep 3, 2009
Messages
5
Helped
1
Reputation
2
Reaction score
1
Trophy points
1,283
Location
bangalore
Activity points
1,316
Don’t forget about a standard protection which puts a diode in antiparallel with the inductive load.

the current through the inductor might not stop immediately at switch-off if the diode in anti parallel is absent. It that u meant ? Or else what is the purpose of it? So the above diagram i almost right.. Is int it? But its not working at all.
 

alexan_e

Administrator
Joined
Mar 16, 2008
Messages
11,895
Helped
2,021
Reputation
4,158
Reaction score
2,031
Trophy points
1,393
Location
Greece
Activity points
64,377
The transistor in your schematic can only sink current so it can only turn on off the current of the coil, if I understand correctly you want to be able to apply to the coil pulses that change polarity so you will probably need an H bridge and a proper driver too.

Alex
 

sreerajps

Newbie level 4
Joined
Sep 3, 2009
Messages
5
Helped
1
Reputation
2
Reaction score
1
Trophy points
1,283
Location
bangalore
Activity points
1,316
The transistor in your schematic can only sink current so it can only turn on off the current of the coil, if I understand correctly you want to be able to apply to the coil pulses that change polarity so you will probably need an H bridge and a proper driver too.

Alex

Sorry, consider the transistor in fig. as a TIP122 CBE. So will i need an H bridge and a proper driver too ?
 

alexan_e

Administrator
Joined
Mar 16, 2008
Messages
11,895
Helped
2,021
Reputation
4,158
Reaction score
2,031
Trophy points
1,393
Location
Greece
Activity points
64,377
the transistor as it is can apply pulses to the coil, it will let current flow and it will cutoff the current, the question is what do you want to do.
If you want to be able to reverse the polarity on the coil and not just turn it on/off then you need a bridge.

Alex
 

sreerajps

Newbie level 4
Joined
Sep 3, 2009
Messages
5
Helped
1
Reputation
2
Reaction score
1
Trophy points
1,283
Location
bangalore
Activity points
1,316
Yes, i need as how an ac signal works on a coil. Yes it changes its polarity. So i need a bridge.. ! Is that what i can conclude. If so give a simple diag with a bridge suitable for this ckt.

The basic need is, a high power oscillator(50V, 2A at least) but ranging 50Hz to 500Hz. adjustable. Can you relate the whole thing and get me something good for me ?
 
Last edited:

alexan_e

Administrator
Joined
Mar 16, 2008
Messages
11,895
Helped
2,021
Reputation
4,158
Reaction score
2,031
Trophy points
1,393
Location
Greece
Activity points
64,377
The bridge with apply (square) wave pulses to the coil, not sinusoidal signals so I hope that this is what you want.
The difficult part is to give you some king of schematic because you need an H bridge and a proper driver that can get your generators signal and then control the four transistors or mosfets, usually this is done with a microcontroller.
Maybe there is an easier solution but I don't have any recommendation.

Alex
 

Status
Not open for further replies.

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Top