Some datasheets may point to external links for how to set up a part for a particular configuration. THM15-2413WI-ND is an adjustable power supply made by Traco Power. So the question is, how do you actually adjust the voltage on this part?
Application Notes
Some manufacturers may have detailed instructions on how to use a part called application notes. If the manufacturer decides to save some room on the current datasheet, they may provide an external link to these instructions. The second page of the datasheet says, “See application note: https://www.tracopower.com/series/thm-15wi.” Clicking this redirects you to Traco’s part page. If you click the item under Additional Documents that says Application Notes, three documents pop up. You will want to click the one that includes the words “voltage adjustment.” While the application note indicates that the series goes from -10 to 10% there is a caveat for the 15V and 24V modules. These two can span from -10 to 20%, see the Output Voltage Adjustment note on page 2 of the datasheet. The same equations will apply regardless of this difference.
Here is the setup required for step up and step down for convenience:
This particular part number ends in 13WI, so the third row of constants will apply.
Here is an example table of resistance values if you want to step up from 1 to 20% in increments of 5%:
| Voltage Increase % | Adjusted Voltage Output | Resistance Value for Trimmer |
|---|---|---|
| 1% | 15.15 | 161,557 |
| 5% | 15.75 | 28,223 |
| 10% | 16.5 | 11,557 |
| 15% | 17.25 | 6,001 |
| 20% | 18 | 3,223 |
If you want to step down, here is an example table in 5% increments too:
| Voltage Decrease % | Adjusted Voltage Output | Resistance Value for Trimmer |
|---|---|---|
| -1% | 14.85 | 818,223 |
| -5% | 14.25 | 151,557 |
| -10% | 13.5 | 68,223 |
Note that we may not have these exact resistance values, so you will have to round up or down depending on the value. Traco recommends resistors with a rating of at least 1/16W too. Also, keep in mind that the output power must not exceed the rated power.