Grow Light Timers: What They Are and How to Set One for Your Grow

A timer is a small device that switches electrical equipment on and off on a schedule you set, and for growers it's the easiest way to lock in a precise light cycle (like 18/6 in veg or 12/12 in flower) without having to be there. Beyond grow lights, timers can run fans, irrigation and pretty much anything you plug in. Here's what a timer is, how the different types work and how to put one to work in your grow.

What is a timer?

A timer, digital or analog, is a device that switches electrical equipment on and off at specific times. It does this by opening or closing an electrical circuit at the times you program. Put simply, a timer is a clock that decides when your gear turns on and off.

Types of timers

There are a few kinds of timers, each with its own features and uses:

1. Digital timer: Digital timers are versatile and accurate. They offer tons of programming options and are perfect for jobs that need exact schedules, like lighting a grow. They're hugely popular because they're easy to use and flexible.
2. Analog timer: Analog timers are mechanical devices that usually work with a dial and adjustable pins or tabs. They're dead simple and fine for jobs that don't need precise programming. They're handy for gear that runs in regular cycles, like fans.
3. Mechanical timer: Similar to analog ones, mechanical timers are simple devices with no electronics. They run on gears and a spring. They're ideal for basic uses and tend to be durable.

How do you set a digital grow light timer?

Digital timers are everywhere in indoor grows because they let you control your lights with precision. Here's how to program one:

1. Set the clock: Enter the current time on the timer. Make sure it's right, since your whole light cycle depends on it.
2. Program your on/off times: Set when the lights come on and when they go off. Digital timers let you program exact light cycles. For example, you can have the lights come on at 8:00 a.m. and go off at 8:00 p.m. (a 12/12 schedule).
3. Double-check the program: Review your settings to avoid mistakes. Once it's programmed, the timer should switch your lights on and off right on schedule.

Why use a timer in your grow?

Timers, especially digital ones, are a seriously useful tool for growers. Here are some of the perks:

1. Precise light control: Digital timers let you program exact light cycles, which is essential for plants that need specific photoperiods (hours of light per day) to grow and flower.
2. Automation: Timers switch your gear on and off for you, so you don't have to babysit it.
3. Energy savings: Running equipment only when it's needed cuts power use and saves you money.
4. Climate control: Timers are also used to run irrigation systems, fans and other devices in the grow space.
5. Less stress for the grower: Automating with a timer lightens your workload and cuts down on human error.

In short, a timer is a versatile little device that makes daily grow chores easier, especially anything to do with lighting and climate. Whether you're growing a few plants at home or running a big operation, a timer can be a priceless tool for boosting efficiency and results.

What is a timer in a PLC?

In a PLC (programmable logic controller), a timer is a programmable function used to control time-based events in an automated system. PLC timers can switch devices, actions or process sequences on or off after a set period of time or based on time conditions.

PLC timers are used for all kinds of applications, such as:

1. On/off control: They can switch electrical devices on or off after a set delay, for example to control lights, pumps, motors or other equipment.
2. Process sequencing: Timers can control the order of events in an industrial process. On a production line, for example, they can set the time between filling a container and sealing it.
3. Safety delays: Timers can add a delay before certain equipment or processes switch on or off, giving operators time to react or get clear of hazardous areas.
4. Timing device control: Timers can drive other timing functions, like countdown or count-up timers.
5. Pulse or periodic signal generation: Timers can be set up to generate pulses or periodic signals, which is useful in motion control.

There are several kinds of PLC timers, but the two main ones are:

• On-delay timer (TON): A TON timer starts counting when an input switches on and holds off turning the output on until a preset time has passed. It's used to add a delay before an output activates once certain conditions are met.
• Off-delay timer (TOF): A TOF timer starts counting when an input switches off and turns the output off once a preset time has passed. It's used to add a delay before an output deactivates after certain conditions change.

PLC timers are programmed in PLC-specific languages such as ladder logic. The programmer sets the delay time and the conditions under which the timer turns on and off.

Bottom line: a PLC timer is a core function for controlling time-based events in automated systems, and it's used across industrial and process automation to improve efficiency and safety.