Timeline for PTC Thermistor - Schematic Analysis
Current License: CC BY-SA 3.0
4 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Nov 8, 2017 at 11:38 | comment | added | Havefun | I tend to think that the intention was to be able to disconnect the PTC circuit (by pulling the pins to GND/HIGH appropriately) and therefore to keep self-heating at a minimum. Would you agree? However, would it not be more practical to use a transistor-based current source in order to drive the thermistor? What circuit would you prefer over the described one? | |
| Nov 8, 2017 at 10:28 | comment | added | Bimpelrekkie | The problem with the circuit as you've drawn it is that whatever is connected to TEMP, SENSE, REF and VDD pins makes or breaks the functionality of the circuit. Only if SENSE would be pulled low (or high) and REF would be connected to a reference voltage then at TEMP we could measure a temperature dependent voltage. Having a SENSE line like that has the advantage that (most of the) current only flows when SENSE is low and a measurement is being done (which saves power). | |
| Nov 8, 2017 at 10:27 | comment | added | rsg1710 | Somehow this doesnt look correct. There is no DC path for PTC (1K). Also, could you tell me what is the difference between sense and temp? seems similar meaning. Also why 3 pins? I feel voltage across PTC is more than sufficient to sense the temperature difference. I am visualising a circuit more like this : m.eet.com/media/1074719/0202feat1fig2.gif | |
| Nov 8, 2017 at 10:11 | history | asked | Havefun | CC BY-SA 3.0 |
