# David

Member Since: June 20, 2008

Country: United States

• For those wondering, or experiencing issues, a PSU may require minimum loads on one or more lines. Typical load values are 1A on +12v, 0.3A on 5v, and 0.5A on 3.3v. If there are multiple +12v lines then each may require a 1A load. Some PSUs don’t need the loads. Some PSUs will just turn off, others will stay on but have out of spec voltages, and others don’t need loading (they’re internally loaded).

• hmm, it still doesn’t include load resistors to keep the PSU stable and/or on…

• Can someone please measure the resistance of the heating pad? That way I and everyone else can calculate the current and wattage at various voltages. The ‘warmup profile’ is interesting but can’t really be used to figure out how it’ll behave in different applications. The video gives a coarse way of calculating the resistance by stating the current draw at 5v… but I’d rather just know the specs of this thing.

• Can someone please measure the resistance of the heating pad? That way I and everyone else can calculate the current and wattage at various voltages. The ‘warmup profile’ is interesting but can’t really be used to figure out how it’ll behave in different applications. The video gives a coarse way of calculating the resistance by stating the current draw at 5v… but I’d rather just know the specs of this thing.

• I think it’s partly the finish on the board and partly just the heatsinking due to the sizes of the traces. The ground wires were a real pain and the location of the solder points for the binding post wires are inconveniently between the binding post and the fuse clips…

• Depends on the PSU’s requirements. A ‘safe’ number for the 5v minimum load is 300mA (much more than the LED). A PSU may require minimum loads on multiple lines though. Typical PSUs may need 1A on +12v, 0.3A on 5v, and 0.5A on 3.3v. If there are multiple +12v lines then each may require a 1A load.

• The description makes this sound like your one stop shop to use your old ATX PSU as a benchtop supply. Not so, your average PSU will require at least one dummy load for the PSU to stay on and for the voltages to be in spec. Unfortunately I bought based on the description and didn’t take a look at the schematic. Now I’m ordering \$4 worth of components to hack it into a working solution.

At the very least the description should give some indication that your PSU may not stay powered on or the voltages may be far out of spec without one or more dummy loads. Mine seems to only require a load on +12v. Others may require loads on 3.3 and 5v too. I’m buying parts to load all 3 so it’ll work with any PSU.

Please change the design, include the \$4 worth of dummy loads, or at least update the description. The comments section looks like 2 years worth of good number of people having issues with this product.

• I didn’t quit (~6 hours of captchas)… and i’ve been a customer for a few years. I think most people, like me, are frustrated by the thousands of captchas they entered. I’m not ungrateful.

• third year running and nothing to show for it… hours of typing thousands of captchas… captchas will haunt my dreams! I liked the ‘crash the servers’ approach better than this - it at least ended quickly.

• I ended up buying it, dimensions are 28.75x34x53.75mm. I also took it apart and the case is only slightly larger than its contents at the end with the power cord coming in (there is a transformer) so it would be hard to reduce the ‘28.75mm’ dimension. The other end of the case could be reduced if your design required it.

No public wish lists :(

In 2003, CU student Nate Seidle blew a power supply in his dorm room and, in lieu of a way to order easy replacements, decided to start his own company. Since then, SparkFun has been committed to sustainably helping our world achieve electronics literacy from our headquarters in Boulder, Colorado.

No matter your vision, SparkFun's products and resources are designed to make the world of electronics more accessible. In addition to over 2,000 open source components and widgets, SparkFun offers curriculum, training and online tutorials designed to help demystify the wonderful world of embedded electronics. We're here to help you start something.