Can we Create Neural network(Simple one such as Multi Layer perceptron) that only contains positive weights only? I was wondering if there is a specific method to create a well performing neural network with only positive weights (I already tried clipping the weight before training or so and initializing the weights with only positive value ) but still doesn't give a good results so is there any other method to do so ? 

Thank You
One way to do that is to customize the formula to update weights. 

Normally, the formula is something like this:

weight = weight - learning_rate * error


You can change it to:

weight = max(0, weight - learning_rate * error)


This will perform well or not? I have no idea. We can't say much about the guaranteed performance of neural network models in general.

However, if by good results, you mean a model with all positive weights, I believe this one will qualify.