| ??? 02/05/05 20:37 Read: times |
#86627 - Driving a Thermal Print Head Responding to: ???'s previous message |
Yueng Chun Chung said:
I have a Thermal Printer that has a Head Drive Voltage pin (TH) that need at most 2.5A current at running the Head, and i would like to use a 8051 to control the enable and disable the Printer by giving a Logic high and low.
Logic high from I/O pin of 8051 to make the voltage supply to supply the voltage and current to the device, otherwise close it, and i would like to use a PNP power transistor (TIP107) for it, is it okey? Anything need to think before wiring it? Does anybody have tried to interfacing any MCU to Thermal Printer? Any suggestion? Any sample circuit? MCU: AT89C51: Port 0: IOL = 3.2A@0.45V Thermal Printer: need 2.5A current to driving the Head@ 5.0V, 64dots on (Model: Samsung SMP610) Thanks Yes I have done this, many times. Take a look at the Dymo range of thermal label printers. I was responsible for the electronics design of all of them. First I would not recommend using a TIP107. It is a PNP darlington which means its saturation voltage is about 2V at the current you require. Also note that its saturated gain is only about 500; you need 6mA into its base for a saturated current of 3A which is more than you can get from an 8051 port. If you want to use a bipolar part then it would be better to use a two or three stage circuit with a single final transistor to ensure a low VCEsat. Alternatively there is a large range of FETs to choose from. Second you need to be very careful about wiring the head power supply to ensure noise is not introduced into the 8051. HTH Ian |
| Topic | Author | Date |
| Question about controlling power supply? | 01/01/70 00:00 | |
| Pardon ? | 01/01/70 00:00 | |
| should be 3.2mA@0.45V... | 01/01/70 00:00 | |
| Driving a Thermal Print Head | 01/01/70 00:00 | |
| Really ? | 01/01/70 00:00 | |
| Dymo micros | 01/01/70 00:00 | |
| which FETs? | 01/01/70 00:00 | |
| FET suggestion | 01/01/70 00:00 | |
| Caution suggested! | 01/01/70 00:00 | |
| Good Advice | 01/01/70 00:00 | |
| Some question about themral printer | 01/01/70 00:00 | |
| To Yueng Chun Chung and Ian Bell | 01/01/70 00:00 | |
Use of D0 | 01/01/70 00:00 |