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Why are 4QD controllers more expensive than cheap Chinese ones?

The quick answer is quality and support. For instance…..

Support- We design and build our products ourselves, we know what goes into them, how they work, and have many years’ experience in sorting out all the little issues that can occur in the wide variety of projects that our customers build. You just don’t get that from Ebay or Alibaba. Our customer support team never leave a man behind – we keep going until your installation is working properly.

Capacitors – Some of our competitors don’t put in much by way of main capacitors, you can get away with this on the test bench but in the real world that often involves long, thin battery leads, this can result in the capacitors and mosfets working a lot harder than they should, getting hot, and failing early. We put in a lot of capacitance and we spread it around the board by fitting many smaller capacitors, this helps the heat dissipation and gives better ripple performance. But it takes time to fit them.

Mosfets – These are the heart of any motor controller. As I write this a single seller [Mouser] lists 2713 different TO220 mosfets. The range of parameters is large. We take the time to sift through this and carefully evaluate the mosfets we use. We’re looking at current ratings, turn on / turn off times, capacitance values, figures of merit, and many other factors to get the best we can.

Metalwork – It’s a fact – all controllers generate heat. It’s no good having the best mosfets in there if you can’t get the heat out. Our controllers have the mosfets bolted directly to substantial aluminium heatsinks. That said, if you want to run high currents for long periods then you’ll need to think about how to manage that heat, see this article on improving heat dissipation.

Repairability – It’s also a fact that controllers can fail, and there’s a whole variety of reasons why [see this article]. If you are unlucky enough to suffer one of these there is a good chance we can repair your controller, again you just don’t get that from some other suppliers. We’ve also written an article on best installation practise which will help you to stop this happening in the first place.

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