I have this vacuum
and this saw
and when I use it for 5 mins it trips. I know its overloading the switch. So if I get an electrician to fix it what can they do? and how much will it cost? I don't want to run an extension cord through the house.
Matt, You have opened up an interesting subject of which is dangerous if the wrong decission is made. I have experience of my own wiring several homes and buildings in the late 1980's on my days off. However I did this working with a licenced electrician and all were requried to be inspected by a licenced electrical inspector. With this being said of my experience, this is my suggestion.
Depending on what you plan on doing in your shop area would determine on what I would do. If you are planning on using it for more that a table saw and dust collector and with keeping in mind that you may or may not expand this, I would bite the cost and do as both John and Justin suggested and install a sub-panel. If on the other hand you plan on only needing a couple 120 volt circuits and maybe a 220 volt circuit and to save money then I would do as retired electrician, Dennis Marsh suggests and install a small panel.
But as a word of caution unless you have a good understanding of electricity I definately would refer all of this work to that of a licenced electrician. I definatley would not fool around with it and experiment with changing the sizes of the breakers. From what I am gathering from reading the discussions you have a garage with a overhead light and a couple plugs in's that are rated at 110 or 120 volts and they are tripping when you run a saw.
This tells me that you most likely are wired with 14 ga wire and have 15 amp breakers. Increasing this to a 20 amp breaker will be 5 amps above what the wire is capable of handeling. This immediately voids any protection by the breaker as the wire is smoking and or on fire when the breaker finally trips. Depending on the length of wire from the main panel to the plug-in also decreases the amount of amperage that will safely flow through the wire.
If the wiring is 12 ga the max breaker is a 20 amp for 110 or120 volts, however I would be certain that there is no 14 ga wire between the panel and your outlet and that there is no other outlet or wire being fed off the circuit with 14 ga wire.
What Dennis Marsh said about the required inspections and the possibilities of having your fire insurance null and void is very true. The other thing not mentioned here is the possibility of criminal charges arising from injury or death. It is a serious matter and must be dealt with accordingly. Remember this: The very least it can do is burn down your home but possiblitiy can become a lethal incident as well." I'm not trying to scare you but I just want to to see you use caution.
Even the best electrician can make a mistake. I cite a recent incident here in Salem, Oregon where a family had their house rewired from the old knob and tube system to the full upgraded system complete with a new panel and all new wiring from the meter head, main panel thru out the home. A couple weeks later In the middle of the night they were awaken by the house being on fire with the outside wall where the main panel was attached in full flame.
They luckly excaped injury and the fire was extinguished. The fire inspector's report found fault in the new panel in which the neutral wire from the meter was left too loose and it cause enough heat from the electrical load to start the panel burning and it spread from there. Lesson here, electrical is unforgiving and dangerous, and just like your saw it will bite you when you least expect it. Please be careful.
I am a retired electrician. Looks like you have one circuit in your garage. You will have to add another. Based on current prices in Texas it will cost $55 per hour or get a quote from your electrician on running the new circuit. Another thing to consider is if you have room in your breaker box for a new circuit. Most homes do not. A 20 amp piggy back breaker can be used if you have the right brand of box. Is your garage attached to your house? If not, a full 50 or 60 amp circuit is probably your best bet. Then you can wire a number of circuits in the garage.