
You need to try and make every encounter a positive experience. Read up on counterconditioning, and desensitisation: these are your main tools for this problem.
Counterconditioning is going to be the primary thing for now. Currently, your dog sees other dogs as a scary thing (possibly, she may be barking with excitement but the process should yield the same result either way). So you need to begin pairing other dogs with fantastic things. Food works best for this, but if your timing is good, then anything that is rewarding for her. Basically, every time she sees another dog, she gets awesome treats - plural! Feed, feed, feed until the other dog has gone away. Food is a very powerful tool - it gets all the good brain chemistry going which will really help cement a positive association with those dogs.
Desensitisation means gradually exposing her at a pace she is comfortable with - that's the hard part. You should aim to keep her far enough away from dogs that she is not reacting, which is course practically, is not always that easy! Just do your best. If one does come charging over, keep the best treats in the world (or her ball, tuggy etc, whatever the most rewarding thing in her universe is) in your pocket and bring it out quick to distract her, and keep her distracted until they give up and go away. If you can, move with her to use your body to block the other dog, and keep yourself between it and her.
Another tool I find exceptionally useful is 'click the trigger' - I don't know if you're familiar with clicker training (if not, get yourself on youtube, it really makes this whole thing so much faster!) but the idea is to click the INSTANT she spots another dog, and reward well, even if she doesn't look round. Pretty soon, she'll spot a dog then look back to you for her treat and when she's doing that, you can start to click for the look-back as well. That helps reduce her focus on other dogs and increase it on you, and aids the above two processes too.
One other thing: DO NOT PUNISH HER. In any way, and that includes your firm 'no' and/or a check from the half check collar. Cardinal rule of dealing with a reactive dog: ANYTHING that happens to her, be it physical or verbal, can and will be associated with whatever she's focused on at the time. So if you tell her off while she's concentrating on a dog, she'll associate you getting mad with the presence of the other dog and try harder to get rid of it next time, before that can happen. Remember, they cannot think about what they are doing when they are reacting - it is purely that, a reaction. So manage it (avoid, keep distance) and reward the good stuff (non-reaction, click the trigger, looking away, sniffing the ground etc). Learn about calming signals and body language so you can recognise other signals to reward and encourage.