20V @ 10A Firing Power & Amperage Physics: Joule-Lenz Law, Parallel Loads, and Bus Stability

A common misconception among beginner pyrotechnicians is believing that higher voltage automatically equates to superior ignition. In reality, chemical pyrogen beads on electric matches (e-matches) and nichrome wire filaments (Talon clips) do not activate from electrical potential (Volts) alone; they ignite from **thermal energy (Joules)** dissipated within the microscopic bridge wire. According to **Joule's First Law of Thermodynamics**: $$ Q = I^2 \cdot R \cdot t $$ Where: - $Q$ is thermal heat generated in Joules (J), - $I$ is electrical current flowing through the bridge in Amperes (A), - $R$ is bridge wire electrical resistance in Ohms (Ω), - $t$ is pulse duration in seconds (s). Because heat scales with the **square of current ($I^2$)**, doubling the current from 1A to 2A quadruples thermal dissipation ($2^2 = 4$). Conversely, if a weak battery power supply sags under load and current drops from 1A to 0.5A, thermal dissipation plummets by 75% ($0.5^2 = 0.25$). This sudden thermal starvation is the direct physical cause of 'hangfires' (delayed bursts) and misfires.

When connecting multiple fireworks or flame projectors to a single channel, shooters must choose between parallel and series wiring. fireTEK's 20V @ 10A architecture is optimized to handle both extremes with complete predictability.

Consumer and low-cost commercial systems rely on 9V alkaline batteries or internal rechargeable packs connected directly through relays. When 8 parallel matches are fired, the effective resistance drops to under 0.3Ω. Ohms law dictates that 8A is demanded instantaneously. Chemical batteries cannot supply 8A without instantaneous internal voltage collapse (down to 2V–3V), which halts ignition mid-cycle. fireTEK solves this via an industrial two-stage power delivery architecture: 1. **High-Efficiency DC-DC Boost Converters:** Step up internal 3.7V LiPO or external USB-C power to a stable, continuous 20.0V DC bus. 2. **Low-ESR Industrial-Grade Capacitor Storage:** Acts as a zero-latency charge reservoir, discharging up to 10.0A instantaneous peak current in less than 100 microseconds with zero bus sag. 3. **Solid-State Electronic Switching:** High-speed MOSFET gate drivers eliminate mechanical relay bounce, providing microsecond-level timing accuracy.

Standard firing consoles use fixed-duration pulses (e.g. 100ms or 200ms). While effective for firing, dumping 10A through a dead short or a burning bridge wire for hundreds of milliseconds wastes massive battery reserves and causes electrical arc erosion on brass rail terminals. fireTEK firmware incorporates **Real-Time Dynamic Current Monitoring**: - As current begins flowing through the cue, the onboard microcontroller samples loop current thousands of times per millisecond. - In the microsecond the pyrogen bead ignites and physically breaks the wire bridge (current drops toward zero), the system instantly trips the gate driver, closing the circuit. - Standard firing duration typically completes in **8ms to 15ms**. - If an igniter fails to rupture immediately, the module maintains current up to 50ms before safety timeout. For Talon clips or special SFX, custom hold times up to 65 seconds can be programmed directly in the show script.