I am in the process of designing a shock tester for my company. It will basically be a pendulum arm with a fixture that will mount our product to at the end of the arm. The product only weighs a max of 500g plus the weight of the fixture that it is mounted to. The pendulum must be held in position when it is brought up before being let go. This can be done by simply having a mechanical trigger system. However could I use an electric motor that could take the torque from the arm and bring the pendulum but also disengage when the pendulum needs to fall?

Young engineer here, any ideas would be helpful

Nate