The phrase "a small prototype of" is correct and usable in written English.
It can be used when referring to a preliminary model or version of something that is smaller in size or scale.
Example: "We created a small prototype of the new device to test its functionality before moving on to full-scale production."
Alternatives: "a miniature version of" or "a compact model of".
In this work, we developed and evaluated a small prototype of the SROP geometry for proof-of-concept.
The design and analysis of a small prototype of a magnetic levitation system at low-speed using a Halbach-type magnet array is presented here.
Mr. Wong and the project's other creators raised $273,000 through Kickstarter this summer to create a small prototype of the pool, but they are still a long way from seeing the pool built.
She texted a friend studying aerospace engineering, and the two came up with an idea for a small prototype of a car that could drive on the ground or lift off into the air.
China is seeking to master the skills and technology needed to operate a manned space lab for long stretches, and the crew on the latest flight practiced rendezvous and docking exercises with the orbiting Tiangong 1 space module, a small prototype of such a lab.
Astronomers have produced a small prototype of what could one day become a telescope with almost unimaginable resolution.
The excavations in Anakena have revealed that a variety of statues were carved in the early period, among them a smaller prototype of the middle-period busts, which mainly differ from the latter by their rounded heads and stubby bodies.
Therefore, a model need not be simply a smaller prototype of the real thing; it may use words, pictures, or any combination of media.
In this work we are presenting the function of a small prototype (6×100 pixels) of the electronic readout board that has been tested.
A small prototype CPV module of 300 mm × 300 mm was constructed with 2 strings of 14 solar cells in series.
BlueH tested a small prototype in 113m of water off Italy in 2008.
